Social Housing at Maldives (Pkg-I)

Technical Specifications along with indicative BOQ

6. Indicative Bill of Quantities 160 – 205

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

SPECIFICATIONS (CIVIL WORKS)

The general conditions and special conditions of the contract including the

drawings shall be read in conjunction with these technical specifications,

and matters referred to, shown or described in one are not necessarily

repeated in the other. These specifications are comprehensive but may

exceed the requirements of this project.

Notwithstanding the sub-division of the specification into various

headings, every part of it is to be deemed supplementary to every other

part and is to be read with it, so far as it may be practicable so to do, or

when the context so permits

The specifications for the works shall be in accordance with C.P.W.D.

specifications Volume I & II in force (with upto date correction slips)

unless otherwise specified in the nomenclature of individual item or in the

specifications. The entire work shall be carried out as per the latest

C.P.W.D. specifications in force with up to date correction slips up to the

last date of submission of tender.

For the items not covered under CPWD Specifications mentioned above,

the work shall be executed as per latest relevant standards/codes

published by B.I.S. (formerly ISI) inclusive of all amendments issued

thereto or revision thereof, if any, up to the last date of submission of

In case of B.I.S. (formerly I.S.I) codes/specifications are not available;

the decision of the Engineer-in-Charge based on acceptable sound

engineering practice and local usage shall be final and binding on the

The Contractor shall be responsible for furnishing all materials required for

execution of the Works. The Contractor shall submit the source and

method of execution for the Engineer-in-Charge’s review before any

execution. All materials used in the construction of permanent works

required under this Contract shall be of 1st class quality as specified

herein and comply with the latest IS Codes or equivalent. The material

shall be tested before bringing it to the site.

This specification establishes and defines the requirements of various

materials to be used in works. Whenever any reference to IS Codes is

made, the same shall be taken as the latest revision (with all

amendments issued thereto) as on the date of submission of the Tender.

Apart from the IS Codes mentioned in particular in various clauses of this

specification, all other relevant codes related to specific job under

consideration regarding quality, tests, testing and/or inspection

procedures shall be applicable. Reference to some of the codes in various

clauses of this specification does not limit or restrict the scope of

applicability of other referred or relevant codes.

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

In case of any variation/contradiction between the provision of IS Codes

and this section, the provision given in this section shall be followed,

unless the Engineer-in- Charge agrees/consents to follow IS codes or

other proposal of the Contractor as provided in the Contract.

All materials shall be of standard quality and shall be procured from

renowned sources/manufacturers approved by the Engineer-in-Charge. It

shall be the responsibility of the Contractor, to get all

materials/manufacturers approved by the Engineer-in-Charge prior to

procurement and placement of order.

Wherever MAKE is not mentioned, Contractor shall take prior approval of

MAKE complying with the tender specifications however mentioning the

MAKE considered in the Bid submission shall prevail if specified earlier.

Whenever called for by the Engineer-in-Charge, all tests of the materials

as specified by the relevant IS Codes shall be carried out by the

Contractor in an approved laboratory and test reports duly authenticated

by the laboratory, shall be submitted to the Engineer-in-Charge for his

approval. If so desired by the Engineer-in-Charge, tests shall be

conducted in the presence of the Engineer-in-Charge or his authorized

Quality and acceptability of materials not covered under this section shall

be governed by the relevant IS Codes. In case IS code is not available for

the particular material, other codes e.g. B.S. or DIN or API/ASTM etc.

shall be considered. The decision of Engineer-in-Charge in this regard

shall be final and binding on the Contractor.

Whenever asked for, the Contractor shall submit representative samples

of materials to the Engineer-in-Charge for his inspection and approval.

Approval of any samples does not necessarily exempt the Contractor from

submitting necessary test reports for the approved material, as per the

specification/relevant IS Codes.

The Contractor shall submit manufacturer’s test reports on quality and

suitability of any material procured from them and their recommendation

on storage, application, workmanship etc. for the intended use.

Submission of manufacturer’s test reports does not restrict the Engineer-

in-Charge from asking fresh test results from an approved laboratory of

the actual material supplied from an approved manufacturer/source at

any stage of execution of work.

All costs relating to or arising out of the tests and submission of test

reports and or samples to the Engineer-in-Charge for his approval till the

date of issuance of Performance Certificate shall be borne by the

Materials for approval shall be separately stored and marked, as directed

by the Engineer-in-Charge and shall not be used in the Works till these

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

All rejected materials shall be immediately removed from the site by the

Contractor at his own cost.

1.2 General Standards

The facilities shall be completed to high standards of construction and

specification. The facilities shall be technically and functionally suitable to

meet the Engineer-in-Charge's objectives:-

i) The material procured or to be used should be to the satisfaction of

the Engineer-in-Charge before being used for the works intended to.

ii) All sanitary/water supply fixture and fittings shall be of approved

make confirming to IS specifications and with ISI Marks.

iii) Lighting should confirm to NBC for Lighting. All electrical system,

fixtures, fittings etc. should confirm to the requirement of Local

Authority, CPWD specifications, latest IS code etc.

iv) Finishing in the room of all buildings should be complete in all

respects including necessary services works and installations.

v) All moving plant, machinery and apparatus be statically and

dynamically balanced at manufactures work and certificate issued.

1.3 Statutory, Industry and Local Standards

The following standards shall apply unless otherwise stated:-

a) The standards set out in National Building Code of India 2016 & BIS

b) The relevant Development Control Rules/Planning Act/Development

Act/ Municipal Act/any other applicable statutes and local by-laws.

c) The National Electrical Code, 1985

d) The Indian Electricity Act 2003

e) Requirements of the local Water Supply Company, Electricity

Supply Company/ Department

f) Requirements of the Pollution Control Board, Environment

clearances, NOC from Fire department, Forest Department for tree

cutting, Lift license, Explosive department, Aviation authorities if

g) Any other statutory requirement for execution of work and to

occupy the buildings and run the services in all respects

1.4 Unacceptable Materials and Processes

The materials and processes given below must not be used in the New

Facilities or in connection with the New Facilities.

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

a) High alumina cement in structural elements.

b) Calcium chloride as a concrete additive

c) Sea dredged aggregates or aggregates for use in reinforced concrete

d) Asbestos cement products; or asbestos in any other form including

vermiculite containing asbestos fibrous dust

e) Lead or any products containing lead for use in connection with

f) Materials which are generally composed of mineral fibres either man

made or naturally occurring which have a diameter of 3 microns or

less and a length of 200 microns or less or which contain any fibres

not scaled or otherwise stabilized to ensure that fibre migration is

g) Urea formaldehyde

h) Plastics for water storage and delivery that release toxic materials

i) Materials containing vinyl chloride unless risk form carcinogen is

shown to be negligible.

j) Vermiculite containing asbestos fibrous dust

k) Cellulose fibre

l) Polyurethane foam or polyisocyanurate foam unless the risk is

shown to be negligible

m) Plywood with glues, resins and surface treatments that produce

irritant volatiles

n) Decorative finishes containing lead or asbestos

o) Materials containing chlorofluorocarbons (CFCs)

p) Paints and wood preservatives containing pentachlorophenois

(PCPs) tributyl tin oxide (TBTO) or Lindane.

q) Any treatment of materials either before or after installation which

give rise to toxic or hazardous emissions or particles

r) Any other substances generally known at the time of use to be

deleterious to health and safety or to the durability of the works in

the particular circumstances they are used.

1.5 Benchmarks

Prior to Commencement of Construction, the contractor shall in consultation

with the Engineer-In-Charge, establish several site datum benchmarks, their

number depending on the extent of the site. The benchmarks shall be sited

and constructed so as to be undisturbed throughout the period of

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

1.6 Site Investigation

The Engineer-In-Charge has got the soil investigation done and the copy of

the report is for guidance. The contractor shall however inspect the site and

study the findings from the trial pits or bores in order to assess the problems

involved in and methods to be adopted for excavation and earthwork. The

contractor shall ascertain for himself all information concerning the sub-soil

conditions, ground water table periods and intensity of rainfall, flooding of the

site and all data concerning excavation and earthwork.

1.7 Setting Out the Work

The contractor shall set out the works and during the progress of the building

shall amend any errors arising from inaccurate setting out.

During the execution of the work contractor must cross check his work with

the approved drawings. The contractor shall be responsible for all the errors in

this connection and shall have to rectify all defects and / or errors.

1.8 Cleaning Up and Handing Over

Upon completion of the work, all the areas should be cleaned. All floors,

doors, windows, surface and external development area etc. shall be cleaned

down in a manner, which will render the work acceptable to the Engineer-in-

Charge. All rubbish due to any reason shall be removed daily from the site

and an area of at least TEN METRES on the outer boundaries of the premises

will be cleaned by the contractor as a part of the contract. Upon completion of

the project, the contractor shall hand over to the Engineer-in-Charge the

A) Certified reports of tests (materials and workmanship)

B) Written guarantee and certificates and

C) Maintenance manuals

All materials and methods of tests shall conform to the latest CPWD

Specifications with upto date correction slips, rules, regulations and / or

specifications of the following authorities where specified herein as

applicable, Bureau of Indian Standards (BIS) or British Standards code of

practice (BS) in case no equivalent BIS is available. The Engineer-In-Charge

will have the option to have any of the materials tested and if the test result

shows that the materials do not conform to the specifications, such materials

shall be rejected.

1.10 For all RCC Works

Cement conforming to relevant IS Code i.e. IS: 8112 (with latest revision

& amendment) shall be used.

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

In case the Chlorides and/or Sulphates etc. are found in soil and/or

ground water more than the permissible limits, the selection of type of

Cement shall be based on the guidelines given in IS 456 as the direction

of Engineer-in-Charge.

Batch Mix Plant (BMC)

Design mix concrete shall be used from fully automatic & computerized

Batch Mixing Plant. The plant shall conform to BIS Code IS 4925 (latest

version with upto date amendments). The Batch Mixing Plant shall be of

adequate capacity minimum 30 m3/hr. or more.

The minimum cement content to be used for the job is as follows:-

M 15 240 KG/CUM

M 25 330 KG/CUM

M 35 370 KG/CUM

M 40 390 KG/CUM

1. These are minimum quantities of Cement to be used irrespective of

the design mix.

Reinforcement Steel: Corrosion Resistant Steel TMT bars of Fe 500

CRS or more grade/conforming to IS: 1786-2008, IS 13920-2016, IS

456-2000 with all latest editions with up to date amendments and

relevant CPWD specification shall be used.

1.11 Quality Control

The Contractor must ensure that the works conform to the quality

standards upto the satisfaction of the Engineer-in-Charge. The contractor

shall submit his quality enforcement plan for monitoring. The works, plant

and materials shall be subject to tests from time to time as per best

practices in the industry. Wherever mentioned in the Contract, the tests

must be carried out at the Contractor’s expense. The materials, fitting &

fixtures shall be procured from reputed make & vendor’s approved by

NBCC Ltd. The Contractor must also supply samples of such material to

the Engineer- in-Charge of NBCC Limited for approval and they must carry

out the laboratory & field tests as and when required by the Engineer-in-

charge of NBCC Limited and/or in conformity with relevant BIS-Codes.

1.12 General Specification

Water used in construction for all civil & structural works shall be clean

and free from injurious amount of oil, acids, alkalis, organic matters or

other harmful substances, which may be deleterious to concrete, masonry

or steel. The ph value of water sample shall be not less than 6. Potable

water shall be considered satisfactory.

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

Tests on water samples shall be carried out in accordance with IS: 3025

and they shall fulfill all the guidelines and requirements given in IS: 456.

The Engineer-in-Charge may require the Contractor to prove, that the

concrete prepared with water, proposed to be used, shall not have

average 28 days compressive strength lower than 90% of the strength of

concrete prepared with distilled water.

The Contractor is required to get the water tested from an approved

laboratory before starting the construction work and in case the water

contains any oil/organic matter or an excess of acid, alkalis or any

injurious amount of salts etc., beyond the permissible maximum limits

given in IS:456, the Engineer-in-Charge may refuse to permit its use. In

case there is any change in source of water, water samples shall be tested

again to meet the specified requirements.

Water shall be stored in tin barrels, steel tanks or water tight reservoirs

made with bricks/stone or reinforced concrete. Brick/stone masonry

reservoirs shall have RCC base slab and shall be plastered inside, with 1

part of cement and 4 parts of sand and finished with neat cement

punning. These reservoirs shall be of sufficient capacity to meet the water

requirements, at any stage of construction.

Water for curing shall be of the same quality as used for concreting and

masonry works. Sea water shall not be used for preparation of cement

mortar, concrete as well as for curing of plain/reinforced concrete and

masonry works. Sea water shall not be used for hydro testing and

checking the leakage of liquid retaining structures also.

Ordinary Portland cement of 43/53 grade conforming to IS 8112 / IS

12269 shall be used. Sulphate Resistant Cement shall be used for

Concrete works below the Plinth level.

Reinforcement Steel

Corrosion Resistant TMT bars of Fe 500 or more grade/conforming to IS:

1786 (latest edition) and IS 13920- 2016, IS 456:2000 (with update

amendments) and relevant CPWD specification shall be used.

In design calculation, stresses in reinforcement in Stirrups shall be taken

as 415N/mm2 as per IS: 456-2000 and other relevant Codes.

Materials of following specification are to be used in work. The Bidders are

expected to possess and be well conversant with the following IS standard

and code of practice.

Ordinary Portland Cement Conforming to IS

8112 / IS 12269 shall be used; Sulphate

Resistant Cement shall be used for all Concrete

works below the Plinth level.

2. Steel IS 1786, IS 456, IS 13920

3. Vibrator I.S. 7246

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

4. Aggregate I.S. 383, I.S. 515

Shall be clean, free from injurious amount of

Water for mixing oil, salt, acid, vegetable materials and other

and curing substances and harmful to concrete in

conformity to I.S. 456 and I.S. 3025.

7. Binding wire I.S. 280 (galvanized minimum 1.25 mm)

8. Rain water pipe I.S. 2527

9. Construction joints I.S. 3414

Steel Door Frame I.S. 4351/75

Conforming to I.S. 7452/82 strictly conform to

Fitting & Fixtures

I.S. specification and as per direction of

for joinery works

Engineer-in- Charge.

Note: In case of any doubt and absence of provision, regarding

specification, respective I.S. with latest amendments shall be referred

(Indian standard).

Items of Work included but not limited to the following:

1.12.1 Benchmark - Prior to Commencement of Construction, the contractor

shall in consultation with the Engineer-In-Charge, establish several

site datum benchmarks, their number depending on the extent of the

site. The benchmarks shall be sited and constructed so as to be

undisturbed throughout the period of construction.

1.12.2 Engineer-In-Charge has got the soil investigation done and the copy

of the report is for guidance. The contractor shall however inspect the

site and study the findings from the trial pits or bores in order to

assess the problems involved in and methods to be adopted for

excavation and earthwork. The contractor shall ascertain for himself

all information concerning the sub-soil conditions, ground water table,

periods and intensity of rainfall, flooding of the site and all data

concerning excavation and earthwork.

1.12.3 Setting Out: The contractor shall set out the works and during the

progress shall amend any errors arising from inaccurate setting out.

During execution of the work contractor must cross check his work

with the approved drawings. The contractor shall be responsible for all

the errors in this connection and shall have to rectify all defects and /

All materials and methods of tests shall conform to the latest CPWD

Specifications with upto date correction slips, rules, regulations and

/ or specifications of the following authorities where specified herein

as applicable, Bureau of Indian Standards (BIS) or British

Standards code of practice (BS) in case no equivalent BIS is

available. The Engineer-In-Charge will have the option to have any

of the materials tested and if the test result shows that the

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

materials do not conform to the specifications, such materials shall

1.12.5 Site quality control

The contractor shall provide in his quality assurance programme

information to show that a system will be used to ensure that all

works carried out under this section will comply with all the

requirements of this section

1.12.6 Antiquities

Any ancient carvings, relics, coins or other curiosities discovered

during the excavation or other work shall remain the property of

the Local Government and shall be handed over to NBCC.

1.12.7 Cleaning up and handing over

Upon completion of the work, all the areas should be cleaned. All

floors, doors, windows, surface and external development area etc.

shall be cleaned down in a manner, which will render the work

acceptable NBCC. All rubbish due to any reason shall be removed

daily from the site and an area of at least TEN METRES on the outer

boundaries of the premises will be cleaned by the contractor as a

part of the contract. Upon completion of the project, the contractor

shall hand over to NBCC the following.

A) Certified reports of tests (materials and workmanship)

B) Written guarantee and certificates and

C) Maintenance manuals

1.12.8 Earthwork in excavation & filling shall be done as per CPWD

Specifications with upto date correction slips. The Contractor shall

be responsible to take all necessary steps to prevent the sides of

trenches from caving in or collapsing. Contractor shall also make all

necessary arrangements for dewatering & drainage as required to

carry out proper excavation & other construction activities as

required and directed by the Engineer-in-Charge, by bailing or

pumping out water, which may accumulate in the excavation pit

either due to ground water, seepage, springs, rain or any other

cause/ source whatsoever. Dewatering of Pits shall be done with

methodology approved by the Engineer-in-Charge. Nothing extra

amount shall be claimed by the contractor on this account and his

quoted rates shall be deemed to have been included for total

dewatering, including sub-soil water also.

1.12.9 Plain and Reinforced Concrete shall be with conformity to I.S.456

and relevant BIS Codes/ CPWD Guidelines.

1.12.10 Cast in situ Reinforced Cement Concrete Piles shall be provided as

per approved drawings, IS Codes and as per latest CPWD

specifications with all amendments. Pile Load Test (Vertical Load

Test, Lateral Load Test, Pile Integrity Test, Pull Out Test on Piles)

shall be carried out in accordance with IS Code of practice IS :

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

2911 (Part IV) and as directed by the Engineer-in-Charge.

1.12.11 Foundation shall be with conformity to relevant BIS Codes/CPWD

Guidelines with up-to-date revisions & amendments.

1.12.12 All RCC works shall be done as per Drawings and CPWD

Specifications.

1.12.13 Reinforced Cement Concrete works upto Second floor level and

above Terrace level shall be executed with conventional shuttering

work as per CPWD Specifications.

1.12.14 Reinforced Cement Concrete works above Second floor level and

upto Terrace level shall be executed with customized Aluminium

Formwork as per CPWD Specifications. Aluminium Formwork shall

be using grade 5052 aluminium of panel sheets of minimum 4 mm

thick and grade 6061 (Type-6) aluminium for extruded sections.

Ready Mix Concrete confirming to IS 4926-1976 shall be used.

Specified strength based on 28-day compressive strength of 15-cm

cubes tested in accordance with IS: 456-1964 shall be the basis of

required RMC. Admixtures shall be as per CPWD Specifications with

upto date correction slips and relevant IS Codes

1.12.15 Corrosion Resistant Reinforced Steel of grade of Fe 500 or

more for reinforcement steel works and cutting, bending, binding in

position shall be done as per CPWD specifications.

1.12.16 The autoclaved aerated concrete blocks having oven dry density

550 to 650 kg/cum, fire resistance minimum 2 hours. Autoclaved

Aerated Blocks for masonry work shall be with conformity to

I.S.2185 Part-III and relevant BIS Codes/ CPWD Guidelines.

The blocks shall be stored on the site on a level ground, protected

against weathering.

Laying of mortar: the mortar shall not be spread so much ahead of

the actual laying of the units that it tends to stiffen and lose the

plasticity there by resulting in poor bond. Consistency as per

requirement of site must be maintained at the point of laying over

bed. Mortar joint shall be struck off flush with wall surface and

when the mortar starts stiffening, it shall be compressed tightly

1.12.17 Cement plastering shall be with conformity to relevant BIS Codes

and as per CPWD Specifications with upto date correction slips.

1.12.18 Mortar shall be with conformity to I.S.2250 and relevant BIS

Codes/CPWD Guidelines.

1.12.19 False Ceiling in Toilets: 8mm thick calcium silicate board false

ceiling with necessary frameworks shall be provided as per latest

CPWD specifications with all amendments.

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

1.12.20 Waterproofing for sunken portion & Under Ground Tank:

Cementitous water proofing as per latest CPWD Specification.

Specialized Agency shall be engaged for the work who is having at

least not less than five years’ of experience of similar nature &

minimum two works each of 60% quantum of the work. Prior to

engaging the agency, Approval of the specialized Agency for the

work has to be taken from the Engineer-in-Charge.

The contractor shall have to furnish ten years guarantee to maintain

the Water Proofing area.

1.12.21 Anti-Termite Treatment : Providing anti-termite treatment using

approved quality of chemical emulsion, spraying the mixture

uniformly by sprayer as pre-constructional anti-termite treatment and

creating a chemical barrier under and around the column pits, wall

trenches, top surface of plinth filling, junction of walls & floors along

with external perimeter of the building, expansion joints, surrounding

the pipes and conduits etc. complete at the rate as directed by the

manufacturer confirming to IS:6313 (Part-II) and as per direction of

Engineer-in-charge including cost of all materials, labour, taxes,

sundries, T&P etc. complete.

The Contractor shall have to furnish 10 years Guarantee to maintain

the anti- termite treated area/structures free from termite

1.12.22 All Stone work (Marble & Kota stone) shall be done as per CPWD

Specifications.

1.12.23 Flush Door Shutters (including minimum 25mm thick Teakwood

lipping) shall be provided and fixed as per relevant BIS

Codes/CPWD Guidelines. All accessories like handle, tower bolt,

door buffer, door stopper, shutter latch shall be made of Powder

coated Aluminium and to be provided/fixed as specified and

approved by Engineer-in-Charge.

1.12.24 Aluminium Doors & Windows :

Aluminium glazed doors, windows etc. shall be of sizes, sections

and details as shown in the drawings. The details shown in the

drawings may be varied slightly to suit the standards adopted by

the manufacturers of the aluminium work, with the approval of

Engineer-in-Charge. Before proceeding with any fabrication work,

the contractor shall Design to suit the load of wind pressure etc.,

prepare and submit complete fabrication and installation drawings

for each type of glazing doors, windows, ventilators and partition

etc. for the approval of the Engineer-in-Charge.

Aluminium, Polyester Powder coated (minimum thickness of powder

coating 60 micron) of approved color & shade, extruded sections of

approved manufacturers shall be used for fixed/openable windows,

ventilators, partitions, frame work & doors etc. shall be suitable for

use to meet architectural designs to relevant works and shall be

subject to approval of the Engineer-in-Charge for technical,

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

structural, functional and visual considerations. The aluminium

extruded sections shall conform to IS 733 and IS 1285 for chemical

composition and mechanical properties. The stainless steel screws

shall be of grade AISI 316. The permissible dimensional tolerances

of the extruded sections shall be as per IS 6477 and shall be such

as not to impair the proper and smooth functioning/operation and

appearance of door and windows. In case of Powder coating, The

powder used for powder coating shall be Epoxy/polyester powder of

make approved by the Engineer-in-Charge.

Glass of 6mm thickness to be used in glazing for openable and fixed

windows and 10mm thick toughened glass for doors etc. should

provide clear completely undistorted vision and reflection. It shall

be free from any bubbles, waves or blemishes. Glass used shall be

of required sizes as per Drawings.

All Gaps in between aluminium frame & adjacent RCC/ Brick/ Stone

work shall be filled up by providing weather silicon sealant over

backer rod of approved quality as per architectural drawings and

direction of Engineer-in-charge complete.

1.12.25 Precast Chequered tiles shall be provided as per latest CPWD

specifications with all amendments.

1.12.26 52mm thick Concrete flooring with non-metallic hardener shall be

provided as per as per latest CPWD specifications with all

amendments and Hardener as per manufacturer’s specifications.

1.12.27 Tremix flooring shall be provided as per latest CPWD specifications

with all amendments.

1.12.28 Floor level shall be maintained during casting of RCC slab to

accommodate the various types of flooring level. No extra payment

shall be made for this. Cement concrete screed of 1:2:4 mix of

required thickness shall be laid in true line and level to receive the

flooring (Tiles, stone etc.), for which nothing extra shall be payable.

1.12.29 All Painting works shall be done as per relevant IS Codes as per

latest CPWD specifications with all amendments.

1.12.30 All Mild Steel work like Railing, Door frames, Door shutter, Truss

etc. shall be as per latest CPWD specifications with all amendments.

1.12.31 Steel painting shall be with conformity to I.S. 1477 (Part-I & Part-

II) and relevant BIS Codes/CPWD Guidelines.

1.13 All works shall be executed as per latest CPWD specification document

with up to date correction slips (if any). Specifications not covered in

CPWD specifications are as under :-

a) All exposed surface of underground reinforced concrete element

shall be protected with two coats of Rubberised bitumen

waterproofing paint, the strokes of each layer to be opposite to

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

each other. Before painting the surface shall be thoroughly cleaned

to make the surface dust free.

b) Waterproofing for Roof : Specialized Agency shall be engaged for

the work who is having at least not less than five years’ of

experience of similar nature & minimum two works of 60%

quantum of the work. Prior to engaging the agency, Approval of the

specialized Agency for the work has to be taken from the Engineer-

in-Charge.. Water proofing of roof shall be executed as per

Specification detailed below:

APP Membrane (4mm thick Non-Woven Polyester

Reinforced) Waterproofing System-

Strictly comply with installation instructions in manufacturer’s

published literature, including but not limited to the following:

Cleaning the surface areas thoroughly so that they are free of all

contaminants like dirt and laitance & to remove all the loose

materials by various mechanical means. Removal of all surface

imperfections, protrusions, loose concrete & filling of cracks

using SBR latex modified Mortar in the ratio Cement: Sand (1:4)

and 5% by weight of cement.

The area of membrane to be laid in a working day should not

exceed that which can be effectively protected in the same

working period, in order to ensure that the membrane is not

subjected to any traffic. The Surface to be applied shall be

completely dry.

After due site preparation and cleaning apply the bituminous

primer at the consumption rate of 0.3 Kg/ Sqm or as specified

by the manufacturer depending on the porosity of the substrate.

Lay out the first complete roll of APP Membrane and align with a

chalk line set out on the floor.

Unroll one roll half way along the membrane to maintain

Fuse the thermo fusible film on the bottom side of the

membrane with a gas torch. When the film melts, immediately

roll the membrane forward and press firmly on the substrate to

Roll the applied membrane immediately with a wooden roller to

release any entrapped air.

Repeat this process with the second half of the roll

The next roll or length should be aligned against the previously

applied piece allowing for minimum 75mm side overlaps and

100 mm end overlap.

All edges and laps should be rolled to ensure proper contact and

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

bond of the laps.

On vertical sections ,

• After surface preparation apply Bitumen Primer at the

consumption rate of Kg/ Sqm depending on the porosity of the

• Terminate the first layer of APP membrane on parapet after

providing fillet of 50mm x50 mm) and fill it with approved

materials as per manufacturer and terminate membrane at min

300mm at FFL by making a groove of 20mm X20mm and

sealing the same with a bitumen sealant. , filling the groove by

• Providing and applying a protection plaster 12 – 15 mm thick

admixed with integral waterproofing compound of approved

make confirming to IS 2645.

Providing a protection screed of minimum 75 mm average

thickness laid in slope admixed with integral waterproofing

compound confirming to IS 2645 at the rate recommended by

the manufacturer. Screed shall be in 1:2:4 Cement Concrete

using of 125gms of synthetic Polyester triangular fibre (fibre of

length 12 mm effective diameters 10-40 microns and specific

gravity of 1.34 to 1.40) for 50 Kg cement used as per directions

of Engineer-in-Charge.

Required Nos. of Khurras shall be provided as per latest CPWD

specifications with all amendments

The contractor shall have to furnish ten years guarantee to maintain the

Water Proofing area.

c) Wooden Frames for Doors : Door frames shall be manufactured

and fixed as per drawings and CPWD specifications. Frames shall be

manufactured from seasoned good quality Red Mirandi wood.

d) PVC Doors for Toilets – PVC door shutters shall be minimum

24mm thick with necessary PVC frames as per manufacturer’s

specifications.

e) Tiling works on floors : Anti-skid/mat finish Ceramic Tile (size

600mm x 600 mm /300mm x 300mm) of approve make shall be

laid in flooring on leveled surface using approved quality Cement

based polymer modified tile adhesive (minimum 3mm thickness) of

approved make, uniformly as per manufacturer’s specifications in

line and level in approved design and filling the joints with epoxy

based joint filling compound of matching shade etc. complete in all

respect including cost of materials, carriage, all labour etc.

complete as per specification and direction of the Engineer-in-

f) All tile/stone flooring work shall be protected from any damage

Signature of Contractor NBCC

Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

from the movement of any tools, plants, equipment at all times

during construction by use of a suitable strong, impervious film or

fabric securely held in place.

g) Tiling works on wall, skirting: Ceramic Tile (size 600mm x

600mm/ 450mm x 450 mm /300mm x 300mm) of approve make in

dados / skirting shall be fixed on plastered surface using approved

quality Cement based polymer modified tile adhesive (minimum

3mm thickness) of approved make, uniformly as per manufacturer’s

specifications in line and level in approved design and filling the

joints with epoxy based joint filling compound of matching shade

etc. Complete in all respect including cost of materials, carriage, all

labour etc. complete as per specification and direction of the

Engineer-in-Charge.

h) Fire Door : Providing & Fixing 46mm thick Fire check Door Frame

& Shutter of 2hr fire rating confirming to BS: 476 Part 22 and IS:

3614 Part II for stability and integrity. Fire doors should be tested

at CBRI Roorkee or equivalent Lab approved by the Engineer-in-

Charge for maximum rating of 2hrs with vision panel. Pressed

Galvanized steel Single/Double leaf door, shutter, infill and finish as

detailed below and conforming to IS 277 complete as per directions

of Engineer-in-charge. Door frame shall be single rebate profile of

125mm x 75mm made out of 1.60mm (16gauge) thick galvanized

steel sheet. Door Frames shall have butt joint and field assembled

with self-tabs / nut bolts. All provision should be mortised, drilled

and tapped for receiving appropriate hardware. Frames should be

provided with back plate bracket and anchor fasteners for

installation on a finished plastered masonry wall opening. Door to

be fixed with 2 hour fire rated stainless steel ball bearing hinges

125mm x 75mm x 3mm, in SS 316 (4 hinges per leaf of shutter).

Suitable for door weights upto 120kgs, Panic bar as per door leaf

(single leaf/ double leaf) Panic Hardware consisting of Main Panic

Latch component, End Component, Push bar, Striker Kit, end caps,

complete set with screws & fixing accessories, External trim, having

fire rated door closer TS 71/68 rack and pinion door closer EN size

3/4, with std. arm and with two independent closing valves and

latching speed adjustable by arm. Full plastic cover should be as

per EN 1154 life cycle 500,000 with seals and door stopper of

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

TECHNICAL SPECIFICATIONS

PLUMBING & SANITARY WORKS

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

The Employer Requirements - present the Contract Conditions, Requirements

of employer for 600 nos. 2BHK flats at residential building ‘Social Housing,

Hulhumale, Maldives. This section gives an overall description of the

construction specifications, some of the design standards and construction

methodology pertaining to PLUMBING & SANITARY SYSTEM.

The contractor shall wherever applicable shall refer equivalent Maldives

Euro/British Codes/Utility Regulation Authority Guidelines/MNDF Regulations

for various specifications of works laid out in this document. However, in case

of non-availability of codes in above mentioned documents for carrying out

any respective works as laid in this document, Indian Standards (Central

Public Works Department (CPWD) Specifications 2019 Volume I & II for

building works and Specification for Road and Bridge Works (Fifth Revision) –

2013, Ministry of Road Transport & Highways (MoRTH)) shall supersede. The

contractor in this case shall submit a Detailed Specifications document based

on relevant Maldives/ Euro or British Codes for approval from client before

execution. Items which are not covered in construction specification neither in

CPWD and MoRTH specification, same shall be executed as per sound

engineering practice and shall be approved by Engineer-In-Charge prior to

commencement of particular item

1.1. Drawings and Technical Documents

All the drawings are to be prepared in computer through AutoCAD which

should provide means of integrating with other discipline's models.

Drawings shall include layouts for pump room, typical toilets drawings showing

exact location of supports, flanges, bends, tee connections, reducers, detailed

piping drawings showing exact location and type of supports, valves, fittings

etc., external insulation details for pipe insulation, electrical panels

inside/outside views, power and control wiring schematics, cable trays,

supports and terminations.

These drawings should be containing all information required to complete the

design and Execution of the Works and also details of construction, size,

arrangement, operating clearances, performance characteristics and capacity

of all items of equipment including the details of all related items of work.

Each item of equipment/material proposed must be a standard catalogue

product of an established manufacturer from the list of approved makes.

Manufacturer’s drawings, catalogues, pamphlets and other documents are to

be maintained in the records office. Each item in each set shall be properly

labeled, indicating the specific services for which material or equipment is

used, giving reference to the governing section and clause number and clearly

identifying the items and the operating characteristics.

Samples of all materials like valves, pipes, insulation, control wires etc. are to

be maintained at site in a dedicated samples room.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

All plumbing system drawings shall be read in conjunction with civil and other

utility drawings.

1.2. Technical Data

Not with standing anything contained in the Employer’s Requirements, the

voltage rating for equipment shall be as follows:

• phase equipment: 433 V ±5%

• phase equipment: 230 V ±10%

2. Design Criteria

The plumbing System shall be designed to cater the entire footprint of the

residential facilities designed for 2BHK Residential construction. The system

should be capable of catering to the full load requirements.

3. Plumbing Systems

3.1. Distribution

Water distribution for the flats shall be carried out with the help of following:

• Installation, Testing & Commissioning of Hydro pneumatic pump

(minimum 3 Working +1 Standby) system for domestic water supply with

all necessary provisions for the same is deemed to be included in the

scope of work. (Hydro pneumatic pump system shall be supplied free of

• Pump shall be having minimum capacity of 410 LPM at 85 M head.

• The pumps shall be provided with the above hydro pneumatic system with

variable speed pumps which would automatically start on and off

depending on the applied load

The hydro pneumatic system envisaged is to operate on the principle of

sensing pressure variations in the plumbing network actuated by pressure

switches at pre-defined pressures in the system.

In case of marginal loads on the plumbing network during lean periods of

residential activities only predefined numbers of pump sets will run so as to

maintain adequate pumping pressures in the network. In the event of increase

in water supply demand, additional pump (s) shall cut-in to meet the

increased demand. This would facilitate optimizing the energy consumptions

without compromising on the performance requirements as opposed to

conventional water supply system. Also, optimization of power will be

achieved by using variable speed pumps which are automatically adjusted to

the varying demands.

The hydro pneumatic system will have inbuilt electronic control panels which

will facilitate pressure settings thereby protecting the system from excessive

pressures and the equipment from burn out. Also, this system would prevent

the occurrence of water hammer in plumbing system by varying the pressures

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

The water distribution system shall be provided at pump room at stilt level of

individual Tower. The water from the MWSC existing water supply line,

pipeline shall be connected to suction of hydro-pneumatic pumping system.

The water shall be distributed to individual flat from the individual line. From

the individual line, water shall be supplied to toilet & kitchen by the individual

3.2. Hot Water

Provision of Hot water supply for the master bed room toilets is to be

3.3. Sewer Drain Systems

System Concept

The system is designed for the following:

• Natural grading of the site.

• Layout of different facilities in the building

• Levels of road and other services in the Vicinity.

• Sub-soil water table.

• Soil conditions

Approach to Planning

The System is designed as a separated system for soil and waste water up to

the first manhole, based on conventional water carriage method.

From the first manhole, the combined sewage is to be conveyed by gravity

through a network of pipes and manholes up to the Plot boundary including

connection to the MWSC Trunk line/ manhole.

The drainage system is a 2-pipe system in accordance with the MWSC, in

which the soil and waste pipes are to be distinct and separate with

independent vents. The disposal from water closets is connected to the soil

stack and local manholes directly and the waste pipes through a trapped gully.

All traps of water closets and the urinals are completely vented in the system.

The vent pipe shall also to be connected to the manhole at ground level.

Design Criteria

The sewer drain system is designed in accordance with design criteria

stipulated in the MWSC published and National and International practices on

the subject. These criteria are as follows:

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

a. Flow of sewage : 80% of water supply (peak flow)

b. Peak flow : 3 times average flow

c. Min. diameter of pipe : 150/200 mm dia

d. Min. velocity in pipe : 0.6 mps

e. Max. velocity in pipe : 3 m / second

f. Flow conditions in pipes:

Pipes up to 400 mm dia : 0.50 full running

Pipes above 400 mm dia : 0.67 full running

Min. depth of pipe below

For branches : 0.6 m

For other : 1.0 m

Formula for calculation and

h. : Manning’s Formula

design of sewer lines

3.4 Rain Water Disposal

In general, the rain water from terraces shall be collected through the down-

take pipes connected to nearest storm water catch basin. Size of catch basin

shall be as per drawing approved with the complete requirement.

All plumbing installations must follow all relevant and prevailing rules, norms

and regulations.

Components should be labeled and numbered according to wiring diagrams.

The water distribution system is provided at pump room which is provided at

stilt level. The water from the MWSC existing water supply line, pipe is

connected suction of hydro-pneumatic pumping system. The water is

distributed to individual flat from the individual line. From the individual line,

water is supplied to toilet & kitchen by the individual pipe line.

3.6 Sanitary Fixtures & Fittings

General Requirement

Sanitary appliances and fixtures for toilets shall be chromium plated brass

fittings subject to approval from the employer’s representatives.

All fixtures and accessories are fixed in accordance with a set pattern

matching the tiles or interior finish. Wherever necessary, the fittings are

centered to dimensions and pattern.

Fasteners to be used shall be half round head chromium plated (CP) brass

screws with CP brass washers.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

All materials to be used shall be rust-proof. Materials in direct or indirect

contact are to be compatible to prevent electrolytic or chemical (bimetallic)

Joints / gaps between all sanitary appliances / fixtures and the floor / walls

shall be caulked with an approved mildew resistant sealant having antifungal

properties of color and shade to match that of the appliances / fixture and the

Water Closet

European W.C. of glazed vitreous China shall be wash down, single or double

siphonic type, floor mounted set, flushing by means of Low level PVC

flushing cistern as specified in the Bill of Quantities. Flush pipe/bend shall be

connected to the W.C. by means of suitable rubber adopter.

Each W.C. seat cover is to be so fixed that it remains absolutely stationary in

vertical position without falling down on the W.C. Seat cover shall be white

solid plastic, elongated open front with heavy duty hinges. Exposed fixture

trims shall be Chrome plated and trims of similar function shall be of the same

Flushing cistern provided for WC shall be low level PVC Cistern of approved

Wash basins shall be vitreous China and under counter in toilets.

Each basin is provided with CI brackets, clips and basin to be securely fixed to

Each basin is to be provided with 32mm diameter CP waste with overflow,

pop-up waste or rubber plug and CP brass chain. The drain outlet is connected

through CP bottle trap and the CP connector pipe.

Bottle trap (for wash basins, sinks etc.) shall be deep seal (minimum 60mm

water seal) cast brass Bottle, heavy chromium plated. All bottle traps are to

be provided with suitable cleaning eye, extension Piece, flare nuts, all

chromium plated. Bottle traps are of approved make and design. Traps for

washbasins, urinal and sinks shall be 32mm

HEALTH FAUCET

A chromium plated spray with integral hand control valve connected to a

flexible pipe and angle valve with wall flange and hook are to be provided as

shown on the drawings or as directed by the Project Manager.

2 WAY BIB TAP

These are chromium plated brass heavy quality of “EGO” type or equivalent,

and are easy type with capstan head. The size is as per design required.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

Double bowl Stainless steel (SS-316) Sinks shall be provided without drain

board based on the requirements.

Each sink is to be provided with painted MS or CI brackets and clips. Counter

top sinks is fixed with suitable painted angle iron brackets or clips. Each sink

is provided with 40mm dia CP waste and rubber plug with CP brass chain. The

MS angle is provided with two coats of red oxide primer and two coats of

synthetic enamel paint. The drain outlet is connected through CP bottle trap

and the CP connector pipe.

3.7 Water Supply (Cold & Hot)

3.7.1 Piping Materials

The piping system for all application other than concealed piping shall consist

of POLO-UV ML5 & POLO-POLYMUTAN ML5 PPr PE 80 GLASS REINFORCED

PIPES and fittings conforming to AS standards.

The piping system for vertical water supply is to be done with POLO-UV ML5 &

POLO-POLYMUTAN ML5 PPr PE 80 GLASS REINFORCED PIPES and fittings

conforming to applicable Code Requirements.

The piping system of internal UPONOR PEX or equivalent piping system with

brass lead-free fittings, NSF approved with crimp joints as required complete.

Galvanized Iron Pipes & Fittings

The pipes shall be galvanized mild steel welded (ERW) or (HFW) screwed and

socketed conforming to the requirements of MWSC. The galvanizing must be

conforming to MWSC with uniform zinc coating, adherent reasonably smooth

and free from such imperfections as flux, ash and drop inclusions, bare

patches, black spots, undulations, lumpiness, runs, rust strains, bulky white

deposits and blisters.

3.7.2 Piping Installation Support

Piping system is to be properly supported with supporting / hanging system as

per the standards.

Pipe work and fittings are to be supported by hangers or brackets allowing

free expansion and contraction. All accessories and ancillaries of support

system such as bracket, saddles, clamps, hanger etc. shall be hot dip

galvanized after fabrication. Further to permit free movement of common

piping, supports shall be from a common hanger bar, fabricated from

galvanized steel sections.

Pipe hangers shall be provided at the following maximum spacing:

Pipe Dia (mm) Hanger Rod Dia mm) Spacing between Supports

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

Insulated piping shall be supported in such a manner that there will be no

undue pressure on the insulation. 14-gauge metal sheets are to be provided

between the insulation and the clamp, saddle or roller, extending at least 15

cm on both sides of the clamps, saddles or roller.

Pipe sleeves, larger diameter than pipes are to be provided wherever pipes

pass through walls and slab and annular space filled with fibre glass and

finished with retainer rings.

All buried pipes for CWS must be cleaned and coated with two coats of

bitumen and then wrapped with two layers of 400-micron polythene sheet

Automatic air valves shall be provided at the top of pipe. All high points in the

piping system are with venting. Vent valves are 15mm pipe size and are

associated with an equal size isolation ball valve.

Discharge from the air valves shall be piped through a galvanized steel pipe to

the nearest drain or sump. All pipes are pitched towards drain points.

Pressure gauges are to be provided at required locations.

The ferrules for connection with main piping system shall be generally

conforming to MWSC. It’s of non-ferrous materials with a bell mouth cover

and is of nominal bore. The ferrule if fitted with a screw and plug or valve

capable of completely shutting of the water supply to the communication pipe,

as and when required.

3.9 Water Meters

The water meters should be conforming to requirements stated by the

Respective Local Authorities. Suitable valves and chambers or wall meter box

to house the meters are to be provided along with the meters.

The meters must be conforming to MWSC.

All water supply system are to be tested to hydrostatic pressure of at least

one and a half (1.5) times the maximum working pressure but not less than

10 Kg /cm2 for a period for not less than 4 hours.

System may be tested in sections and such sections are entirely to be re-

tested as a complete network on completion of total works.

All valves (gate, globe, check, safety) are of gun metal suitable for the

particular service. All valves are of the particular duty and design. Valves all

either shall be of screwed type or flanged type, with suitable flanges and non-

corrosive bolts and gaskets. Tail pieces are to be supplied along with valves.

Gate, globe and check valves must be conforming to local standard and non-

return valves and swing check type reflux to local standard.

Sluice valves, where specified shall be flanged sluice valves of cast iron body.

The spindle, valve seat and wedge nuts shall be of gunmetal. They are

generally have non-rising spindle and are of the particular duty and design.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

The valves are to be supplied with suitable flanges, non-corrosive bolts and

asbestos fibre gaskets. Sluice valves shall be conforming to local standard.

Ball valves with floats to be fixed in storage tanks shall consist of cast brass

lever arm having copper balls (26 SWG) screwed to the arm integrally. The

copper ball is bronze welded seams. The closing/opening mechanism

incorporating the piston and cylinder is non-corrosive metal and include

washers. The size and construction of ball valves and float is suitable for

desired working pressure operating the supply system. Brass valves are

supplied with brass hexagonal back nuts to secure them to the tanks and a

socket to connect to supply pipe.

Globe valves on water line are union bonnet with stem/disc and body seat ring

of SS-316. Suitable for temperature up to 80° C.

Sl No Type of Valve Size Construction Ends

15 mm to 50 mm Gun Metal Screwed

a. Isolating Valve

65 mm and above Gun Metal Flanged

b. 65 mm and above Cast Iron Flanged

Butterfly Valve

G.M. non return 15 mm to 50 mm Gun Metal Screwed

valve 65 mm above Gun Metal Flanged

Flap Type – Non

d. 65 mm and above Cast Iron Flanged

All valves are suitable for the working pressure involved.

3.11.1 Pressure Reducing Valve Set

Each pressure reducing valve set is complete with pressure reducing or

pressure regulating valve, isolating valves, pressure gauges on inlet and

outlet, pressure relief valve on outlet and filter on inlet.

Each pressure reducing valve is comprising of loading neoprene diaphragm

and a full floating, self-aligning, ignition resistant seat and is of the single

stage, pressure reduction type with provision for manually adjusting the

delivery pressure. The valve should not fail to the low pressure.

Valves should be capable of operating and maintaining automatically the

respective delivery pressure and flow rates and are not be liable to creep.

Valves are also to be capable of maintaining the pre-set downstream pressure

under static condition.

The filter on each inlet to a pressure reducing valve shall be of replaceable

porous sintered metal type.

3.12 Pressure Gauge

The pressure gauge shall be constructed of die cast aluminium and stove

enameled. It’s weather proof with an IP 55 enclosure. It’s a stainless steel

(SS-316 grade) bourdon tube type pressure gauge with a scale range from 0

to 16 Kg / Sq.cm. and shall be constructed in accordance with international

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

code. Each pressure gauge shall have a siphon tube connection. The shut off

arrangement shall be by ball valve.

3.13 Water Fittings

All gunmetal fittings such as gate, globe, check and safety valves are to be

fitted in pipe line as per the requirements for efficient operation of water

distribution system. Necessary unions are to be provided on both ends of the

valves for the purpose of easy replacement.

3.14 Connections to RCC Water Tanks

All pipes crossing through RCC work must have puddle flanges fabricated from

GI pipes of required size and length and welded to 6/8 mm thick GI plate. All

puddle flanges must be fixed in true alignment and level to ensure further

connection in proper order.

Full way gate valves of approved make are to be provided as near the tank as

practicable on every outlet pipe from the storage tank except the overflow

pipe. Overflow and vent pipes are to be terminated with mosquito proof

The overflow pipe shall be so placed to allow the discharge of water being

readily seen. A stop valve is also to be provided in the inlet water connection

to the tank. The outlet pipes are to be fixed approximately 75mm above the

bottom of the tank towards which the floor of the tank is sloping to enable the

tank to be emptied for cleaning.

3.15 Pipe Protection (For Cold Water Pipes Buried In Trenches / Ground /

All buried pipes are to be cleaned with zinc chromate primer and AW4 pypkote

protection shall be applied.

3.16 Thrust Blocks

In case of bigger pipes (80 mm dia and above), thrust blocks of cement

concrete 1:2:4 (1 cement: 2 coarse sand: 4 graded stone aggregate of 20

mm nominal size) shall be constructed at all bends.

3.17 Masonry Chamber

• All masonry chambers for stop cocks, sluice valves and meter etc. are to

be built based on the requirement.

• Concrete means cement concrete 1:3:6 (1 cement: 3 coarse sand: 6

graded stone aggregate 40 mm nominal size for bottom and cement

concrete 1:2:4 (1 cement: 3 coarse sand: 6 graded stone aggregate 20

mm nominal size for top slab.

• AAC Block masonry in cement mortar 1:5 (1 cement: 5 fine sand)

• Inside Plaster shall be minimum of 12 mm thick in cement mortar 1:3 (1

cement: 3 fine sand) finished with a floating coat of neat cement.

3.18 Internal Drainage (Soil, Waste, Vent & Rain Water Pipes)

3.18.1 Piping System

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

Scope of work

• Work under this section consists of furnishing all labour, materials,

equipment and appliances necessary and required to completely install all

soil, waste, vent and rainwater pipes and fittings as required by the

approved drawings.

• Without restricting to the generality of the foregoing, the soil, waste, vent

pipes system includes the following: -

o Vertical and horizontal soil, waste, vent pipes, and fittings, joints,

clamps, connections to fixtures.

o Connection of all pipes to sewer lines as shown on the drawings at

ground floor levels.

o Drainage, channels, gratings & floor drains.

o Floor and urinal traps, cleanout plugs, inlet fittings and rainwater

heads/Khurras Testing of all pipe lines

3.18.2 General requirements

• All materials shall be new and of the best quality conforming to

specifications and subject to the approval of Project Manager.

• Pipes and fittings must be fixed truly vertical, horizontal or in slopes as

required in a neat workmanlike manner.

• Pipes shall be fixed in a manner as to provide easy accessibility for repair

and maintenance and not cause obstruction in shafts, passages etc.

• Pipes must be securely fixed to walls and ceilings by suitable clamps

intervals specified.

• Access doors for fittings and clean outs shall be so located that they are

easily accessible for repair and maintenance. Any access panel required in

the civil structure, false ceiling or marble cladding etc. are clearly reported

to the Employer in the form of shop drawing so that other agencies are

instructed to provide the same.

3.18.3 Piping System

Schedule of Pipes Use

1 uPVC pipes 75, 110,

Vertical stacks for Soil, Waste, Vent & RWP

160 & 210 mm dia

2 uPVC pipes 40, 50 & Horizontal For Soil, Waste. Vent pipes pvc

63 mm dia pipes (welded joints) 6 kg/sqcm class III

3.18.4 Soil, Waste & Vent Pipes

• The Soil & Waste Pipe System above ground has been planned as a "two

pipe system" as defined in MNWS having separate pipes for waste for

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

kitchen sinks, showers, washbasins and floor drains and is approved by

Project Manager.

• All waste water from pump rooms, floor channels are to be provided with a

deep seal trap before connecting to the main drain or vertical stack.

• Vertical soil & waste stacks shall be connected to a separate horizontal

drain at ground level generally as shown on the approved drawings.

• Toilet layouts have been so arranged that the W.C. outlets are with “P”

trap above ground.

3.18.5 Rainwater Pipes

• All open terraces are drained by rain water down takes.

• Rainwater down takes shall be separate and independent of the soil and

waste system and are to discharge into Catch Basin/harvesting pits/

Drainage system of the Complex.

• Rain water in open courtyards are collected in catch basins and connected

to the storm water drain.

• Any dry weather flow from waste appliances e.g. waste water sumps shall

be connected to sewers after traps and not in the storm water drainage

3.18.6 Balcony drainage

Wherever required, all balconies, terraces, planters and other formal

landscape areas are to be drained by vertical down takes or other type of

drainage system shown on the approved drawings and directed by the

Architect/Project Manager

3.18.7 uPVC Pipes & Fittings

• Soil, Waste and Anti-siphonage pipes and fittings are uPVC. All pipes are

straight and smooth conforming to MWSC or as specified in approved

• Pipes and fittings for main vertical stacks & branches 110 mm, & 75 mm

dia are Soil, Waste & Rainwater System known in the short form as SWR

drainage system with injection moulded fittings with approved type of

socket & ‘O’ rubber ring joints.

• Joints are done as per the manufacturer’s recommendations. The pipes and

fittings must have matching dimension for perfect joints in the system. ‘O’

ring fittings must have sufficient gap (approx. 10 mm) for thermal

expansion of pipes.

• uPVC pipes are to be clamped to the wall with approved type uPVC saddle

clamps/U clamps and G.I. rod fixed to the angle iron support system within

• Use proper uPVC pipe adapters for connections between cast iron pipes,

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

traps & uPVC pipes where necessary. Such joints are made of an approved

type of ‘Putty’.

For UPVC pipes standard UPVC clamps are used. For other pipes M.S.

clamps, supports and hangers provided are galvanized. Factory made Pre-

fabricated clamps are preferred. Contactor may fabricate the clamps of special

nature and galvanize them after fabrication but before installation. (Clamps

are fabricated from mild steel sections) All nuts, bolts, washers and other

fasteners are factory galvanized.

• Clamps shall be of approved designs and fabricated from M.S. flats and

other sections of thickness and sizes as per drawings or contractor’s

shop drawings. Clamps are fixed in accordance to manufacturer’s

details/shop drawings to be submitted by the contractors.

• When required to be fixed on RCC columns, walls or beam are to be

fixed with approved type of galvanized expansion anchor fasteners

(Dash fasteners) of approved design and size according to load.

• Structural clamps e.g. trapeze or cluster hangers fabricated by electro-

welding from M.S. Structural members e.g. rods, angles, channels,

flats as per Contractors shop drawing are to be galvanized after

fabrication. All nuts, bolts and washers must be galvanized.

• Galvanized slotted angle/channel supports on walls are provided

wherever shown on drawings. Angles/ channels are of sizes shown on

approved drawings. Angles/channels are fixed to brick walls with bolts

embedded in cement concrete blocks and to RCC walls with anchor

fasteners mentioned above. The spacing of support bolts on support

members fixed horizontally is not exceeding 1 m.

3.19.1 Floor traps

Floor traps where specified are of multi inlet uPVC traps (SWR) having a

minimum 50 mm deep seal. The trap and waste pipes when buried below

ground is set and encased in cement concrete blocks firmly supported on firm

ground or when installed on a sunken RCC structural slab. The blocks are in

1:2:4 mix (1 cement: 2 coarse sand: 4 stone aggregate 20 mm nominal size).

Contractor shall provide all necessary shuttering and centring for the blocks.

Size of the block is 30x30 cm of the required depth.

3.20 Cleanout plugs

Floor Clean out Plug.

Clean out plug for Soil, Waste or Rainwater pipes laid under floors shall be

provided near pipe junctions, bends, tees, “Y’s” and on straight runs at such

intervals as required as per site conditions. Cleanout plugs shall terminate

flush with the floor levels. They will be threaded and provided with key holes

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

for opening. Cleanout plugs shall be Cast Brass screwed to a G.I. socket. The

socket is lead caulked to the drain pipes.

3.21 Waste pipe from appliances

• Waste pipe from appliances e.g. washbasins, sinks and urinals shall be

uPVC in all toilets, kitchen, pantries and service areas where so required,

and as given in the Schedule of Quantities or shown on the drawings.

• All pipes are to be fixed in gradient towards the connection to stack, trap

or drain. Pipes inside all toilets shall be in chase unless otherwise shown

on approved drawings where so required and shown on drawings or

directed by the Project Manager.

• Galvanized pipes (Where specified or required at site for waste only)

conforming to MWSC (medium class) and quality certificates are

furnished. Pipes are to be provided with all required fittings e.g. tees,

couplings, bends, elbows, unions, reducers, nipples, plugs. All G.I. waste

pipes are to be terminated at the point of connection with the appliance

with an outlet of suitable diameter. Pipes in chase shall be painted with

two coats of black bitumen paint and exposed pipes with one coat of

red oxide primer and two or more coats of synthetic enamel paint or as

given in the Schedule of Quantities.

Laying and Jointing

The pipes are laid and clamped to wooden plugs fixed above the surface of the

wall. Provision is made for the effect of thermal movement by not gripping or

disturbing the pipe at supports between the anchors for suspended pipes. The

supports are allow the repeated movements to take place without abrasion.

Jointing for UPVC pipes are made by means of solvent cement for horizontal

lines and ‘O’ rubber ring for vertical line. Where UPVC pipes are to be used for

rain water pipes, the pipe is finished with GI adopter for insertion in the RCC

slab for a water proof joint.

UPVC pipes require supports at close intervals. Recommended support spacing

for un-plasticized PVC pipes is 1400 mm for pipes 50 mm diameter and above.

Pipes are aligned properly before fixing them on the wooden plugs with

clamps. Even if the wooden plugs are fixed using a plumb line, pipe also be

checked for its alignment before clamping, piping are properly supported on,

or suspended from clamps, as required. Pipe supports are primer coated with

anti-corrosive.

3.22 Pipes Hangars, Supports, Clamps Etc.

All pipes clamps, supports and hangers shall be galvanized. Factory made

prefabricated clamps are preferred. All nuts, bolts, washers and other

fasteners are factory galvanized.

Structural clamps e.g. trapeze or cluster hangers shall be fabricated by

electro-welding from MS structural members e.g. rods, angles, channels flats

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

and galvanized after fabrication. All nuts, bolts and washers shall be

3.23 Rain Water Pipes

All open terraces are drained by rain water down takes UPVC.

Rainwater down takes are separate and independent of the soil and waste

system and is discharge into the underground storm water drainage system of

Rainwater in open courtyards are collected in catch basins and connected to

the storm water drains.

Any dry weather flow from waste appliances, e.g. AHU’s pump rooms, waste

water sumps are connected to sewers after traps and not in the storm water

drainage systems.

3.24 Pipe Sleeves

Pipe sleeves, next larger diameter than pipes are provided wherever pipes

pass through walls and slabs and annular space filled with fiberglass and

finished with retainer rings. All pipes are accurately cut to the required sizes in

accordance with relevant BIS codes and burrs removed before laying. Open

ends of the pipes are closed as the pipe is installed to avoid entrance of

foreign matter.

3.25 Pipe Protection

Cast iron soil and waste pipes under floor in sunken slabs and in wall chases

(when cut specially for the pipe) are encased in cement concrete 1:2:4 mix (1

cement: 2 coarse sand: 4 stone aggregate of 12 mm size) 10 cm bed and

around. When pipes are running well above the structural slabs, the encased

pipes are supported with suitable cement concrete pillars of required height

Soil, waste, vent and rain water pipes in exposed location, in shafts and pipe

space shall be painted with two or more coats of ready mix oil paint to give an

even shade. Before painting all dust and extraneous matter are to be

Pipe in chase is painted with two coats of bitumen paint, covered with

polythene tape and a final coat of bitumen paint.

CI Soil and waste pipes below ground and covered in cement concrete are not

3.27 Commissioning

3.27.1 Pre-commissioning

The water storage tanks and pipes are first be filled with water and thoroughly

flushed out. The storage tanks are then be filled with water again and

disinfecting chemical containing chlorine added gradually while tanks are

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

being filled to ensure thorough mixing. Sufficient chemical is used to give

water a dose of 50 parts of chlorine to one million parts of water.

If ordinary bleaching powder is used, the proportions are 150 gm. of powder

to 1000 liters of water. The powder are mixed with water in the storage tank.

If a proprietary brand of chemical is used, the proportions are specified by the

manufacturer. When the storage tanks are full, the supply is stopped and all

the taps on the distributing pipes are opened successively working

progressively away from the storage tank. Each tap is closed when the water

discharged begins to smell of chlorine. The storage tank is then be filled up

with water from supply pipe and added with more disinfecting chemical in the

recommended proportions. The storage tank and pipe are then remain

charged at least for three hours. Finally, the tank and pipes are thoroughly

flushed out before any water is used for domestic purpose.

• The pipework is to be thoroughly flushed before supply is restored.

• After the pipework is tested and approved, but before it is coupled, it is

to be sterilized with a solution of chloride of lime.

• Prior to start-up and hydraulic testing, all pumping systems are to be

flushed and drained at least once thoroughly to get rid of contaminating

materials. All pipes are to be rodded to ensure clearance of debris,

cleaning and flushing are carried out.

• All strainers are to be inspected and cleaned out or replaced.

• When the entire systems are reasonably clean, a pre-treatment

chemical shall be introduced and circulated for at least 8 hours.

• Remove oil, grease and foreign residue from the pipework and fittings;

• Pre-condition the metal surfaces to resist reaction with water or air.

• Establish an initial protective film;

• After pre-treatment, the system is drained and refilled with fresh water

and left until the system is put into operation.

o Check all clamps, supports and hangers provided for the pipes.

o Check all the equipment, piping and valves coming under hot water

system and operate each and every valve on the system to see if

the valves are functioning properly.

o Fill up pipes with water and apply hydrostatic pressure to the

3.28 EXTERNAL SEWERAGE & DRAINAGE

3.28.1 Excavation

3.28.1.1 Alignment and grade

The sewer pipes shall be laid to alignment and gradient shown on the

drawings but subject to such modifications as shall be ordered by the Project

Manager. No deviations from the lines, depths of cutting or gradients of

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

sewers shown on the plans and sections shall be permitted except by the

express direction in writing of the Project Manager.

3.28.1.2 Excavation in tunnels

The excavation for sewer works shall be open cutting unless the permission of

the Project Manager is obtained for laying pipes in tunnel where sewers have

to be constructed along narrow passages or difficult ground.

3.28.1.3 Opening out trenches

In excavating the trenches, etc. the solid road metalling, pavement, kerbing,

etc. and turf is to be placed on one side and preserved for reinstatement when

the trenches or other excavation shall be filled up. Before any road metal is

replaced, it shall be carefully sifted. The surface of all trenches and holes shall

be restored and maintained to the satisfaction of the Project Manager.

The Contractor shall grub up and clear the surface over the trenches and other

excavations of all trees, stumps roots and all other encumbrances affecting

execution of the work and shall remove them from the site to the approval of

the Project Manager.

3.28.1.4 Obstruction of roads

The Contractor shall not occupy or obstruct by his operation more than one

half of the width of any road or street and sufficient space shall then be left

for public and private transit, he shall remove the materials excavated and

bring them back again when the trench is required to be refilled. The

Contractor shall obtain the consent of the Project Manager.

3.28.1.5 Removal of filth

All night soil, filth or any other offensive matter met with during the execution

of the works, immediately after it is taken out of any trench, sewer or cess

pool, shall not be deposited on to the surface of any street or where it is likely

to be a nuisance or passed into any sewer or drain but shall be at once put

into the carts and removed to a suitable place to be provided by the

3.28.1.6 Excavation to be taken to proper depths

The trenches shall be excavated to such a depth that the sewer shall rest on

concrete as described in the several clauses relating thereto and so that the

inverts may be at the levels given in the sections.

3.28.1.7 Refilling

After the sewer or other work has been laid and proved to be water tight, the

trench or other excavations shall be refilled. Utmost care shall be taken in

doing this, so that no damage shall be caused to the sewer and other

permanent work. The filling in the haunches and upto 75 cms above the

crown of the sewer shall consist of the finest selected materials placed

carefully in 15 cms layers and flooded and consolidated. After this has been

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

laid, the trench and other excavation shall be refilled carefully in 15 cms

layers with materials taken from the excavation, each layer being watered to

assist in the consolidation..

3.28.1.8 Contractor to restore settlement and damages

The Contractor shall, at his own costs and charges, make good promptly

during the whole period the works are in hand, any settlement that may occur

in the surfaces of roads, berms, footpaths, gardens, open spaces etc. whether

public or private caused by his trenches or by his other excavations and he

shall be liable for any accidents caused thereby. He shall also, at his own

expense and charges, repair and make good any damage done to buildings

and other property if in the opinion of the Project Manager the damage is due

to his negligence.

3.28.1.9 Disposal of surplus soil

The Contractor shall at his own costs and charges provide places for disposal

of all surplus materials not required to be used on the works. As each trench

is refilled the surplus soil shall be immediately removed, the surface properly

restored and roadways and sides left clear.

3.28.1.10 Timbering of sewer and trenches

a) The Contractor shall at all times support efficiently and effectively the sides of

the sewer trenches and other excavations by suitable timbering, piling and

sheeting and they shall be closed timbered in loose or sandy strata and below

the surface of the sub soil water level.

b) All timbering, sheeting and piling with their walling and supports shall be of

adequate dimensions and strength and fully braced and strutted so that no

risk of collapse or subsidence of the walls of the trench shall take place.

3.28.1.11 Shoring of buildings

The Contractor shall shore up all buildings, walls and other structures, the

stability of which is liable to be endangered by the execution of the work and

shall be fully responsible for all damages to persons or property resulting from

3.28.1.12 Removal of water from sewer, trench etc.

a) The Contractor shall at all times during the progress of the work keep the

trenches and excavations free from water which shall be disposed of by him in

a manner as will neither cause injury to the public health nor to the public or

private property nor to the work completed or in progress nor to the surface of

any roads or streets, nor cause any interference with the use of the same by

b) If any excavation is carried out at any point or points to a greater width than

the specified cross section of the sewer with its envelope, the full width of the

trench shall be filled with concrete by the Contractor at his own expenses and

charges to the requirements of the Project Manager.

3.28.1.13 Width of trench

Recommended width of trenches at the bottom shall be as follows: -

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

100 mm dia pipe 55 cms

150 mm dia pipe 55 cms

225-250 cms dia pipe 60 cms

300..400 mm dia pipe 75 cm

Maximum width of the bed concrete shall also be as above. No additional

payment is admissible for widths greater than specified.

3.28.2 Gully traps

Gully traps shall be of the same quality as described for stoneware pipes in

clause 4.1 above and used where shown on drawings.

Gully traps shall be fixed in cement concrete 1:5:10 mix and a brick masonry

chamber 30x30 cms inside in cement mortar 1:5 with 15x15 cms grating

inside and 30x30 cms C.I. sealed cover and frame weighing not less than 7.3

kg to be constructed as per standard drawing. Where necessary, sealed cover

shall be replaced with C.I. grating of the same size (1 cement: 5 coarse sand:

10 stone aggregate 40 mm nominal size.

3.28.3 Cement concrete and masonry works (for manholes and chambers

3.28.3.1 Materials

Water used for all the constructional purposes shall be clear and free from oil,

acid, alkali, organic and other harmful matters, which shall deteriorate the

strength and/or durability of the structure. In general, the water suitable for

drinking purposes shall be considered good enough for constructional purpose.

b) Aggregate for concrete

The aggregate for concrete shall be in accordance with NFPA. In general,

these shall be free from all impurities that may cause corrosion of the

reinforcement. Before actual use these shall be washed in water, if required as

per the direction of Project Manager. The size of the coarse aggregate shall be

done as per NFPA.

Sand for various constructional purposes and its grading shall comply in all

respects with NFPA. It shall be clean, coarse hard and stone, sharp, durable,

uncoated, free from any mixture of clay, dust, vegetable matters, mica, iron

impurities soft or flaky and elongated particles, alkali, organic matters, salt,

loam and other impurities which may be considered by the Project Manager.

The cement used for all the constructional purposes shall be ordinary Portland

cement or rapid hardening Portland cement.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

e) Mild steel reinforcement

The mild steel for the reinforcement bars shall be in the form of round bars

conforming to all requirements.

The autoclaved aerated concrete blocks having oven dry density 550 to 650

kg/cum, fire resistance minimum 2 hours. Autoclaved Aerated Blocks for

masonry work shall be with conformity to I.S.2185 Part-III and relevant BIS

Codes/ CPWD Guidelines.

g) Other materials

Other materials not fully specified in these specifications and which may be

required in the work shall conform to the NFPA. All such materials shall be

approved by the Project Manager.

3.28.3.2 Cement concrete (plain or reinforced)

a) Cement concrete for pipes bedding, cradles, foundations and R.C.C. slabs for

all works shall be mixed by a mechanical mixer where quantities of the

concrete poured at one time permit. Hand mixing on properly constructed

platforms may be allowed for small quantities by the Project Manager. Rate for

cement concrete shall be inclusive of all shuttering and centring at all depth

b) Concrete work shall be of such thickness and mix as given in the Schedule of

c) All concrete work shall be cured for a period of at least 7 days. Such work

shall be kept moist by means of gunny bags at all times.

3.28.3.3 Masonry work

Masonry work for manholes, chambers and such other works as required shall

be constructed with autoclaved aerated concrete blocks as specified in the

approved drawings in cement mortar of mix as specified. All joints shall be

properly raked to receive plaster.

3.28.3.4 Cement concrete for pipe support

a) Wherever specified or shown on the drawings, all pipes shall be supported in

bed all round or upto haunches. The thickness and mix of the concrete shall

be given in the approved drawings. Width of the bedding shall be the width of

the trench as specified.

b) Unless otherwise directed by the Project Engineer, cement concrete for bed,

all-round or in haunches shall be laid as follows: -

Upto 1.5 m Upto 3.0 m

Beyond 3.0 m Depth

1:4:8 (no sub soil

Mix of concrete 1:4:8 1:4:8

UPVC pipes All round Upto Haunches All round

Mix of concrete 1:3:6 1:3:6 1:3:6

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

UPVC pipes All round All round All round

Under the building 1:3:6 1:3:6 1:3:6

UPVC pipes All round All round All round

(Concrete mix refer to cement: coarse sand: stone aggregate 40 mm

c) Upvc pipes may be supported on AAC Block masonry or precast R.C.C. or in

situ cradles. Cradles shall be as shown on the drawings.

d) Pipes in loose soil or above ground shall be supported on AAC Block or stone

masonry pillars as shown on the drawings.

3.28.3.5 Manholes and chambers

All manholes, chambers and other such works as specified shall be

constructed in AAC Block masonry in cement mortar 1:5 (1 cement: 5 coarse

sand) or as specified in the Schedule of Quantities.

All manholes and chambers etc. shall be supported on base of cement

concrete of such thickness and mix as shown on the drawings.

Where not specified manholes shall be constructed as follows: -

(All dimensions internal clear in cms)

Size of manhole 90 dia 122 dia

at bottom at bottom

Type Rectangular Rectangular Conical Conical

Maximum Depth 150 240 167 239

Average thickness

Size of cover and 60 x 45 50 dia 50 dia 50 dia

Frame mm 116 or 116 or 116 or 116 or

Weight of cover and

All manholes shall be provided with cement concrete benching in 1:2:4 mix (1

cement: 2 coarse sand: 4 stone aggregate 20 mm nom. Size) The benching

shall have a slope of 10 cm towards the channel. The depth of the channel

shall be full diameter of the pipe. Benching shall be finished with a floating

coat of neat cement. as per standard details.

All manholes shall be plastered with 12/15 mm thick cement mortar 1:3 (1

cement: 3 coarse sand) and finished with a floating coat of neat cement

inside. Manhole shall be plastered outside as above but with rough plaster

mixed with water proofing compound.

All manholes with depths greater than 0.8m shall be provided with 20 mm

square or 25 mm round rods aoristic coated catch rings set in cement

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

concrete blocks 25x10x10 cms in 1:2:4 mix 30 cms vertically and staggered.

Foot rests shall be coated with coal tar before embedding.

All manholes shall be provided with cast iron/steel fibre reinforced plastic

(SFRC) covers and frames and embedded in reinforced cement concrete slab.

Weight of cover, frame and thickness of slab shall be as specified in the

Schedule of Quantities or given above.

Road gullies, gratings on drains shall be cast iron with M.S. frame or Steel

Fibre Reinforced Concrete (SFRC) with frame as specified in the approved

drawings / Schedule of Quantities.

3.28.4 Making connections

Contractor shall connect the sewer line of the building to the main manhole by

providing making holes and channels etc.

3.28.5 Measurement

Rates are deemed to be inclusive but not limited to the followings:

a) All kinds of soil including rocks

b) Depth of excavation upto any depth including backfilling, consolidation etc.

c) Timbering and shoring, if required for all depths and types of soil

classifications.

d) Pumping and bailing out water from excavated pits and surface water from

rain falls or broken pipes lines and other similar sources.

Nothing Extra shall be payable on any account whatsoever detailed above.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

TECHNICAL SPECIFICATIONS

FIRE FIGHTING WORKS

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

1. Fire Fighting System

1.1. Classification of Buildings

All residential building is classified as per the MNDF guidelines & NFPA and

also attention is made to the guidelines stated. It is to design the firefighting

system considering the stringent of requirements stated between NFPA &

MNDF following buildings is classified according to the use or character of the

1.2. Wet riser System

The infrastructure for firefighting operation is considering wet riser system in

accordance with guidelines laid down by and as described in MNDF and is

consisting of following (minimum requirement):

• Hydrant pump.

• Jockey pump.

• Diesel engine driven pump.

Suction line of each pump is directly connected to the fire reserve tanks and

discharge is in a common header. 4 Kg/cm2 residual head pressure is to be

maintained at the furthest hydrant.

While actual operation is carried out with the help of electrically operated

hydrant pumps, Jockey pump will take care of hydraulic losses in the system

during normal operation and maintain minimum specified pressure in the

header. Diesel engine driven pump is provided back-up to electrical pumps in

accordance with regulations. Power supply to the firefighting pump panel is

from both city and emergency sources.

Fire hose cabinets (FHC) are to be placed strategically in accordance with

NFPA & MNDF. All floors shall be provided with separate wet riser connected to

the single headed fire hydrant landing valve with fire hose cabinet consisting

of first aid box, swinging hose reels.

1.3. Portable Fire Extinguishers

Portable fire extinguishers of water (Gas pressure) type of 9 liters capacity,

6KG DCP fire extinguisher (gas cartridge type) and 2kg stored pressure fire

extinguisher are to be provided as first aid fire extinguishing appliances.

Fire Blankets shall be conforming to BS EN 1869: 1997 or any other equable

International Standard. Fire Blankets must be extremely flexible and can be

draped easily. The slim pack of fire blanket must be Red or White. The Fire

Blankets is got to be approved by the MNDF fire and Rescue Service before

Installation. Special permission should be taken if it is different from above.

The appliances are to be distributed over the entire floor area in such a way so

that a person has to travel not more than 10 m to reach the nearest

appliance. These are to be placed or hanged on wall in a group on several

suitable places.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

The number of extinguishers shall be calculated in accordance with MNDF.

Classification of extinguishers is in accordance with the following table:

Suitable Type of

Sl. No. Class of Fire

Fire in ordinary combustibles

i. (wood, vegetable, fibres, rubber Gas Expelled Water Type

plastics, paper etc.

Chemical extinguishers of

Fires in flammable liquids, paints,

ii. carbon dioxide, dry powder

grease, solvents and the like

type and buckets.

Chemical extinguishers of

Fire in gaseous substances under

iii. carbon dioxide and dry

pressure including liquefied gases

Fires in reactive chemicals, active Special type of dry powder

metals and the like extinguishers

The Fire Extinguishers shall be approved by the MNDF fire and Rescue Service

before Installation. Special permission should be taken if it is different from

1.4. Salient Features in Fire Fighting System Design

Below grade areas or blind spaces is protected against flammable fuel/vapour

penetration through structural intervention or mechanically ventilated as per

the requirements stated in MNDF.

Fire hydrants are to be provided in building.

This section deals with the requirements of provision of firefighting services.

The pumps, prime movers & Control panels etc. is installed in the pump

Following is the broad scope of work:

• Fire Hydrant System

• Fire Extinguisher

• Pumps & prime movers

• Electrical panels etc.

1.6. Scope of Work

The broad scope of work is include Design, Procurement, Construction,

Completion, Testing and Commissioning of item as detailed below .

• The scope of work includes design, supply, Erection, coordination

among different trades, liaison/coordination with relevant local

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

government departments, Testing and Commissioning of Fire Protection

system for the proposed Residential building. The Fire Protection scope

covers internal work of the buildings.

• The building is provided with Fire Protection system, as required by the

MNDF requirement, relevant NFPA & local-building regulations

applicable for the project.

• Provision of underground Fire water tank and suitable rating fire

pumping system for the proposed buildings shall be as per MNDF

requirement. Solenoid valve with auto closing and opening, depending

on the tank water level is to be provided. Capacity of the Fire Water

Tank is to be designed as per MNDF.

• All the fire pumps except jockey pumps shall be UL listed and will be

supplied along with UL listed controllers having soft starters with inbuilt

pressures switches.

• Fire Water Pumps & Panel along with associated piping, valves and

accessories shall be as per system requirements. Electrical control panel

for Fire Pumps and cabling / wiring including connection to various FPS

• Fire Hydrant System with piping network, landing valves, Hose Reels,

Hose box and Hose Cabinets as per MNDF requirement.

• Internal Hydrants with associated piping and valves. Location of the

Hydrant Cabinets is coordinated with Architects, other services & must

comply with the applicable codes & standards.

• Portable Fire Extinguishers to fight fire at incipient stage. Fire

Extinguishers are to be provided as per travel distance and area

coverage throughout the building, as per the prevailing codes of MNDF.

• Sealing of cut-outs / openings with Fire sealants. The fire rating of the

sealant should be compatible with the structure (Floor/Wall), as the

• Interface with various other disciplines as per the Specifications. FPS

piping will not run inside the water sensitive areas like TC rooms,

Substations, Generators rooms etc.

• To develop Schematic Riser diagrams, detail working drawings showing

hydrant pipe network, fire hose stations network, pump room layout,

portable Fire Extinguisher locations etc. complete.

• Obtaining Completion Certificate from the Local Fire Officer.

• Provide fire and life safety signage.

• It is responsible for the Supply & Installation of all the above-mentioned

Fire Protection Systems in accordance with the Specifications as

mentioned above.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

1.7. General Specifications

• Pipes and Fittings Pipes for Wet Riser & dry riser system shall be of G.I

C class Pipe. Pipes up to 150mm dia are conforming to MNDF. Pipes

with dia. 200mm and above (6mm thick) is conforming to MNDF. All

pipes must be as per approved makes only (G.I. C-class).

Joint for black steel pipes and fittings shall be metal to metal thread joints. A

small amount of red lead may be used for lubrication and rust prevention.

Joints are not be welded or caulked.

Joints between G.I. pipes and fittings should be made with the pipes and

fittings having "V" groove and welded with electrical resistance welding in an

approved manner. Butt welded joints are not acceptable.

1.8. Pipe Protection

• All pipes in underground masonry trenches/service tunnels, above

ground and in exposed locations are to be painted with one coat of red

oxide primer before installation and two or more coats of synthetic

enamel paint of approved shade after installation.

• Pipes in wall chases are to be protected from corrosion by 2 coats of

bituminous paints.

• Protection of Underground Pipes:

Corrosion protection tape shall be wrapped on G.I. C class Pipes to be buried

in ground. This corrosion protection tape comprises of coal tar/asphalt

component supported on fabric of organic or inorganic fibre and minimum 4

mm. thick and conforming to requirement of MNDF – code of practice for

coating and wrapping of underground G.I. Pipe line. Before application of

corrosion protection tape all foreign matter on pipe are to be removed with

the help of wire brush and suitable primer shall be applied over the pipe

thereafter. The primer is allowed to dry until the solvent evaporates and the

surface becomes tacky. Both primer and tape shall be sourced from the same

manufacturer. Corrosion protection tape is then wound around the pipe in

spiral fashion and bounded completely to the pipe. There is no air pocket or

bubble beneath the tape. The overlaps are 25 mm and 250 mm is leave

uncoated on either end of pipe to permit installation. This area is wrapped in

accordance with the manufacturer’s recommendations. If applications are

done in cold weather, the surface of the pipe is pre-heated until it is warm to

touch and traces of moisture are removed and then primer is applying and

allowed to dry.

1.9. Installation of Pipes

All pipes must be adequately supported from ceiling or walls by structural

clamps fabricated from M.S. structural e.g. rods, channels, angles and flats.

All clamps are to be painted with one coat of primer and two coats of black

enamel paint. It is required to provide inserts at the time of slab casting or

provide suitable anchor fasteners.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

The pipe supports or hangers shall be designed to withstand combined weight

of pipe, pipes fittings, fluid in pipe and insulation. Pipe supports shall be of

steel and coated with rust preventing paint and finished with two coats black

enamel paint. The maximum spacing for pipes supports shall be as below:

Pipe (MM) Spacing (MTR) Size of support

150 & above 3.0 12mm

Pipes supports shall be spaced at maximum interval of 1.5 mtr. on either side

of heavy fitting and valves. Wherever piping passes through walls, pipes

sleeves of diameter larger than that of piping is to be provided. Pipe sleeves

are of steel or cast iron pipe.

The underground piping shall be supported with AAC Block masonry pedestal

blocks of suitable size and strength provided at an interval of 3.0 mtrs. The

pipes are laid at 1 mtr depth (top of the pipe) and trench excavated for

sufficient width. The rate for pipe is including the scope of excavation/refilling

the trench. 1:2:4 concrete thrust blocks are also to be provided at turning of

pipe. The cost of installation includes concrete pedestals etc. as required and

to be included in the item rate.

1.10. Internal Hydrants

• The Single headed Internal Hydrant outlet is as per MNDF

• A cap with chain shall be provided on the head of the outlet. The hydrant

shall have an instantaneous pattern female coupling for connecting to Hose

• The Landing Valve is of fitted to a Tee connection on the wet riser at the

• The Hydrant is constructed from gun metal and finished to a smooth polish

on screwed ends. The Hydrant is screwed inlet of 80mm dia. Flanged type

with 4 nos. holes. The Hydrant is a PVC plug with chain fixed to the main

body of the Hydrant. The Hydrant is not leak at any screwed joint.

1.11. First‐‐Aid Hose Reel Equipment

• Recess Hose reels approved to BS EN 671-1: 1995, or any other equable

International Standard, Automatic operation, Right or Left hand take off.

Including 30m length of Hose, 19mm diameter Hose approved to PR EN

694, or any other equable International Standard, and Nylon twist

operated Jet/spray Nozzle on mounting plate with integral flexi guide for

Hose withdrawal device. 03 or 04 fixing holes should be provided in

position indicated to suit M8/M10 sized fixing screws or M12 fixing bolts.

With Ball valve inlet and Flexible inlet water Pipe.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

• The overall width of the reel is not more than 850mm. The overall height

of the Reel is less than 850mm including Hose and integral Flexi guide for

hose withdrawal guide. The overall depth of the Hose reel is not more than

150mm. Color of the Reel is Red, fitted with operating instruction plate.

• The Hose Reels and the related equipment’s must be approved by the

MNDF Fire and Rescue Service before Installation. Special permission is

taken for the other size of the Hose reels.

• The Hose Reels nozzle retainer or hose guide and the inlet valve is fitted at

a height of about 900mm above floor level.

• The hose reel cabinet shall be Recess mounting type with or without glass

paneled door for use with the above-mentioned sized Hose Reels. Hose

Reel Cabinet dimension should be no more than 900mm in width, 900mm

in height, 160mm in depth (including door).

• Color of the cabinet is Red. Special permission is taken for other Colour.

• Recessed Latch Type handle is installed. Hose reel signage is in accordance

to BS 5499 or any other equable International Standard. Fixing hole is

• The Hose Reel cabinets are to be approved by the MNDF fire and Rescue

Service before Installation.

1.12. Hose Pipes, Branch Pipes and Nozzles

Two numbers Hose Pipes Internal hydrants is rubber lined woven jacketed

(RRL) and 63mm in dia. 15m long, (non-percolating Reinforced rubber lined)

conforming to MNDF & NFPA. The hose is sufficiently flexible and capable of

being rolled. Length of hose pipe Min 15 m. Each run of hose is complete with

necessary Male & Female Gun Metal coupling at the ends to match with the

landing valve or with another run of hose pipe or with branch pipe. The

couplings is of instantaneous spring lock type. It is conforming to MNDF &

Branch Pipes

Standard short sized Branch pipe is constructed from alloy of Stainless-Steel

(SS-316) material 63 mm dia and be complete with male instantaneous

spring lock type coupling for connection to the hose pipe. The branch pipe is

externally threaded to receive the nozzle conforming to MNDF & NFPA

The Nozzle is of SS-316, 20mm internal diameter. The screw threads at the

inlet connection should match with the threading on the branch pipe. The inlet

end is a hexagonal head to facilitate screwing of the nozzle on to the branch

pipe with nozzle spanner. End couplings, Branch pipe, and Nozzles is confirm

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

1.13. Orifice Plate

The Pressure in a Fire Fighting system varies from point to point. The pressure

is maximum in the pump house and minimum at the furthest hydrant at TOP

level. To reduce pressure to operating pressure at every internal hydrant,

orifice plates are provided before connection of landing valve between the

flanges of landing valve and pipe flange.

1.14. Fire Brigade Inlet Connections

Fire Brigade Inlet connection is provided near the pump house as specified for

the following purposes: -

• Fire brigade inlet connection to DRY riser with the sluice valve & non-

• The locations of these fire brigade connections are suitably decided with

the approval of Engineer-in-charge and with a view that these are easily

accessible to the fire brigade, without any possible hindrance.

1.15. Valve Chambers

It is to provide suitable AAC Block Masonry Chamber in cement mortal 1:4 (1

cement: 4 coarse sand) on cement concrete foundations 150 mm thick in

1:5:10 mix (1 cement: 5 fine sands: 10 graded stone aggregate 40 mm

normal size) 12 mm thick plaster inside and outside finished with a floating

coat of neat cement inside with cast iron surface box approved by fire brigade

including excavation, back filling complete.

1.16. Fire Extinguishers

1.16.1 Portable Fire Extinguishers

Portable fire extinguishers is selected, installed, inspected and maintained in

accordance with guidelines stated in MNDF.

1.16.2 Water Type Extinguisher (Gas Pressure Type)

The Extinguisher medium is primarily water stored under normal pressure; the

discharge being affected by release of Carbon Dioxide Gas from a 120 gms

The capacity of Extinguisher, when filled upto the indicated level, shall be of 9

The skin thickness of the cylinder is fabricated from Mild Steel sheet, welded

as required, with dish and dome, being of same thickness, and of size not

exceeding the diameter of body. The diameter of body shall be not less than

150 mm and not exceeding 200 mm. The neck is externally threaded up to

minimum depth of 16 mm, and leaded tin bronze.

The cap is of leaded tin bronze, and screwed on the body up to a minimum of

1.6 cm depth, with parallel screw thread to match the neck ring. The siphon

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

tube shall be of brass or G.I and the strainer of brass. The cartridge holder,

knob, discharge fittings and plunger to be of Brass / Leaded tin bronze, and

plunger of stainless steel (approved grade), spring of stainless steel

(approved grade). It is a snifter valve to act as breather. The cap is with

handle fixed to it. The discharge hose is of braided nylon, of 10 mm dia and

600 mm long, with a nozzle of brass fitted at end.

The extinguisher is treated for anti-corrosion internally and externally, and

externally painted with Fire Red paint. The paint is stove enameled / powder

coated. The cartridge shall be as per MNDF, and have 60 gm. net carbon

dioxide gas for expelling. The extinguisher, body and cap is treated to an

internal hydraulic pressure of 25 kg/cm². It is external marking with letter A,

of 2.5 cm height, in TS - ELECT.- 493 block letters within a triangle of 5 cm

each side. The extinguisher is upright in operation, with the body placed on

ground, and discharge tube with nozzle held in one hand to give a throw of

not less than 6 meters, and continue so for at least 60 sec. The extinguisher

body is clearly marked with international standard.

1.16.3 Carbon Dioxide Extinguisher

The Carbon Dioxide Extinguisher is as per MNDF & NFPA

The Body is constructed of seamless tube conforming to MNDF & NFPA and

having a convex dome and flat base. Its dia is maximum 140 mm, and the

overlay height is not exceeding 720 mm.

The discharge mechanism is through a control valve conforming to MNDF &

NFPA. The internal siphon tube is of copper or aluminum conforming to

relevant specifications.

Hose pipe is high pressure braided Rubber hose with a minimum burst

pressure of 140 kg/cm², and is approximately 1.0 meters in length having

internal dia of 10 mm. The discharge horn is of high-quality unbreakable

plastic with gradually expanding shape, to convert liquid carbon dioxide into

gas form. The handgrip of Discharge horn is insulated with Rubber of

appropriate thickness.

The gas is conforming to MNDF and is stored at about 85 kg/cm². The

expansion ratio between stored liquid carbon dioxide to expanded gas is 1:9

times and total discharge time is minimum 10 sec. and Maximum 25 sec.

The extinguisher is fulfilling the following test pressures: a) Cylinder: 236

kg/cm² b) Control Valve: 125 kg/cm² c) Burst pressure of Hose: 140 kg/cm²

It is an upright type. The cylinder, including the control valve and high-

pressure Discharge Hose is comply with relevant Statutory Regulations, and

be approved by chief Controller of Explosives.

The Extinguisher including components is as per MNDF.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

1.17. Power and Control Panel and Other Control Components

This section covers the detailed requirements of the power and the control

panel for the wet riser system, and also for the various control components in

1.18. Power and Control Panel

1.18.1 Constructional Requirements

General Features

The power and control panel is totally enclosed, free standing floor mounted

cubicle type, fabricated out of sheet steel not less than 2mm thick. Wherever

necessary, additional stiffening is to be provided by Galvanized MS angle iron

framework. General construction is of compartmentalization and

sectionalisation such as mains incomers, electric fire pump, diesel fire pump,

pressurization pump, and control, so that there is no mix up of power and

control wiring and connections in the same sections as far as possible. The

panel is also have the space for cable allays. The space for cable alleys is at

least 200mm wide to the entire depth of panel. The panel is front operated

type with all connections accessible from the front. Front doors are hinged

type. Back doors are hinged type or removable type for inspection. The door

hinges is of concealed type. The doors for bus bar chamber are of removable

type with the help of bolts. The doors are provided with quick fixing doors

knobs with indication. The general arrangement of the panel is got approved

before fabrication the cubicle construction is as per MNDF.

1.18.2 Cable entries and gland plates

All cable entries are through gland plates which are removable and

sectionalized. Where heavy cables are brought in and terminated, suitable

clamps are incorporated to relieve the stress on the glands due to the weight

of the cable. Cable entries may be from top or bottom depending on the

equipment layout and cable scheme as approved.

1.18.3 Bus bar and Connections

The busbars is air insulated, and of aluminium of high conductivity electrolytic

quality and of adequate cross section. Current density is not exceeding 1.3

amps. per sq.cm. All connections to individual circuits from the busbars are

preferably with solid connections. The busbars and the connections are

covered with PVC sleeves or in an approved manner. Busbars are suitably

supported using non-hygroscopic insulated DMC/SMC supports. High tensile

bolts and spring washers are to be provided at bus bar joints.

1.18.4 Earthing Arrangement

GI strip 25mm x 5mm is run at the rear of the board. 2 nos. earth terminals

are to be provided at the ends of the GI strip for connection to earth system.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

1.18.5 Terminal Blocks and Small Wiring

Terminal blocks are of heavy duty type and generally not less than 15 amps

250V grade upto 100V, and 600V grade for the rest of the functions. They are

easily accessible for maintenance. All control wiring inside the panel is with

PVC insulated copper conductor FRLS of 2.5 sq.mm. size and 600V grade

conforming to as per MNDF. Suitable color-coding is adopted. Wiring harness

is neatly formed and run preferably function wise, and as far as possible

segregated voltage wise. Identification ferrules are used at both ends of the

1.18.6 Instruments and Lamps

All indication lamps and instruments shall be flush mounted type in front of

the panel. The voltmeter and ammeter size shall be 100mm nominal (dial

size) conforming to MNDF.

A necessary ammeter with selector switch is to be provided with suitable

Current Transformer.

Indicating lamps to indicate the availability of electric supply is to be provided

at the incoming section. Necessary indicating lamps for alarm indications and

battery charging are provided in the respective sections.

All indicating lamps and meter is protected with HRC cartridge type fuses. /2

Amp back up MCB.

All internal components shall be provided with suitable identification labels.

Suitably engraved labels are fixed at the panel for all switches, instrument

push buttons, indicating lamps etc.

1.19. Equipment Requirements

The power and control panel is to be comprising of individual section for the

various equipment’s of the system and controls, in a combined cubicle type

design. All switches, MCCBS, MCBS and fuse/fuse switch units is conforming

to relevant MNDF.

1.19.2 Incomer Section & outgoing section

Incomer section:

2 nos. Suitable amps 4 pole MCCB unit complete. One set of 96 mm square

digital Ammeter (0-200 Amps) completes with built in selector switch and

CTS. Two set of 96 mm square digital Voltmeter with built in selector switch

(0 - 500 V) complete with control fuses and selector switch. One set of phase

LED indicating lights with control MCB. One set of 4 strips of 300 Amps

aluminium busbars.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

Outgoing feeder

• One number of Suitable Amps TPN MCCB with built in thermal magnetic

release within built O/C ,S/C & EF safety (25 KA, Ics = Icu) unit

complete, S P Preventer, ML 4 type Contactor for soft starting, start and

stop push buttons, auto-manual switch, digital Ammeter with CTS, ASS,

LED phase indicating lights, Auxiliary Contactors for

interlocking/sequence of operation, control terminals complete in all

respect with interconnections for Hydrant Pump.

• One number of Suitable Amps rated TPN MCCB (10 KA, Ics = Icu)

unit- complete, ML 1.5 type Contactor for D O L starting with overload

relay, start and stop button, digital Ammeter, CTS and selector switch,

phase indicating lights, Auxiliary contacts for interlocking/sequence of

operation, control terminals complete in all respect for Jockey Pump.

Control Wiring from Pressure Switches of different settings in Hydrant and

Jockey Pumps, for sequence of operation is included to complete the system.

Color code with ferrule marking is also made.

The cabling is PVC insulated FRLS and aluminium / copper conductor cable of

1100 volts grade conforming to MNDF as required from Fire Pump Board to

motor and cable of suitable size as per BOQ.

1.19.3 Electric Fire Pump Section

This section is incorporating the following facilities.

• Suitable capacity MCCBS

• Control system components and equipment such as relays, contractors

and timers etc. for automatic operation.

• Starter Unit, Current Transformer and digital ammeter.

• LED Indication lamps, their fuses, terminal block, push buttons, control

and selector switches etc. are as required.

• Pump lock out devices due to faults or abnormalities as specified in

operating sequence.

• Visual/audio alarms, indications and communications facility as specified

in operating sequence.

• Necessary inter-connection and control wiring etc.

1.19.4 Engine Section

The engine section is incorporating the following facilities:

• Control system components and equipment such as relays, contractors,

timers etc. for automatic operation.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

• Instruments, indicator lamps, MCB terminal blocks, push buttons, control

and selector switches etc. as are required.

• Engine shut down and block out devices due to faults or abnormalities as

• Visual/audio alarms and indications as specified.

• Inter-connection and control wiring etc.

1.19.5 Auxiliary Pump Section

The auxiliary pump section for jockey pump is incorporating the following:

• Control system components such as relays, times, contractors, etc. as

are necessary for functional requirements.

• Starter unit, current transformer and ammeter.

• Indication lamps, fuses, terminal blocks, push buttons selector, switch

etc. as required.

• Inter-connections and control wirings etc.

1.19.6 Control Section

This section is incorporated the following: -

• Control components integrating the various sections, so as to satisfy the

functional requirements.

• Battery charger unit with boost/float/Trickle charger facility with

voltmeter, capable of independently charging 2 sets of batteries at a

• Visual/audio alarms covered all alarm, trip indication.

• Lamps healthy test facility.

• Instruments, indicating lamps, push buttons, fuse terminal blocks etc. as

• Test facility to simulate operation of hydrants.

1.20. Other Control Components

1.20.1 Pressure Switches

Pressure switches is to be provided for switching on and off the pressurization

pump at pre-set pressures and also for switching off the fire pump at pre-set

pressure. Being the main component for initiating the signal for the operation

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

of the pumps, the pressure settings is totally reliable, sturdy in construction

and of long life. The pressure settings should be adjustable.

1.20.2 Power Supply for Controls

In order to ensure that the control systems remain co-operational at all times

the control system is designed for 24 VDC operation fed from the battery.

This is independent of the starting battery for the engine i.e. battery is remain

trickle charged at all times from the separate battery charger at the control

2. Electrical Work and Earthing

This section covers the detailed requirements of electrical works including

earthing, for the materials installation.

Electric power supply shall be terminated in the incoming switch gear of the

power and control panel by the Department. All further connections to the

various components of the system is the responsibility of the Contractor, for a

complete and working system, satisfying all the functional requirements.

The scope is particularly including the following:

Power and Control Panel(s) as given in relevant section.

All inter-connections with multi-core armoured copper cables of size suitable

between various control units and control panel(s). All power cable

connections with multi-core armoured aluminium cables of size as specified in

the approved drawings, between panels, motors etc.

Necessary earthing with 2 Nos. G.I. plate electrodes and loop earthing.

2.2. Fire Protection System - Pipe Work

General Requirements

Pipes are fixed in a manner as to provide easy accessibility for repair and

maintenance and not cause obstruction in shafts, passages etc.

Valves and other appurtenances are so located that they are easily accessible

for operations, repairs and maintenance.

Pipe accessories such as gauges, meters, control devices, etc. have the same

working pressure rating as the associated pipework. All pipework is free from

burrs, rust and scale and cleaned before installation. All personnel engaged on

welding operations must possess a certificate of competence issued by an

acceptable / recognized authority.

Pipes of following types are to be used:

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

G.I black pipes in accordance with MNDF heavy grade (for pipes of sizes 150

mm N.B. and below) suitably lagged on the outside to prevent soil corrosion.

G.I. pipes buried below ground are also to be suitably be lagged with 2 layers

of 400-micron polythene sheet over 2 coats of bitumen.

Steel pipelines up to 150 mm diameter shall be in accordance with MNDF,

Part-II (heavy grade) while pipelines above 150 mm diameter shall be in

accordance with MNDF.

All pipe clamps and supports are fabricated from MS steel sections and shall

be factory galvanized before use at Site.

Pipes are hung by means of expandable anchor fastener of approved make

and design. The hangers and clamps are fastened by means of galvanized

nuts and bolts. The size/diameter of the anchor fastener and the clamps are

suitable to carry the weight of water filled pipe and dead load normally

Hangers and supports are thoroughly galvanized after fabrication. The

selection and design of the hanger and support must be capable of carrying

the sum of all concurrently acting loads. They should be designed to provide

the required supporting effects and allow pipeline movements as necessary.

All guides, anchor braces, dampener, expansion joint and structural steel to

be attached to the building/structure trenches etc. are provided.

The piping system are to be tested for leakages at 2 times the operating

pressure or 1.5 time shut-off pressure, whichever is highest including testing

for water hammer effects.

Flanged joints are used for connections for vessels, equipment, flanged valves

and also on two straight lengths of pipelines of strategic points to facilitate

erection and subsequent maintenance work.

For pipes underground installation the pipes are to be buried at least one

meter below ground level and have 230 mm x 230 mm masonry or concrete

supports at least 300 mm high at 3m intervals. Masonry work to have plain

cement concrete foundation (1 cement: 4 coarse sand: 8 stone aggregate) of

size 380x380x75 thick resting on firm soil.

Mains below ground level are supported at regular intervals not exceeding 3.0

metre and laid at least 2.0 metre away from the building.

Piping Installation and Support

Pipe work and fittings are supported by hangers or brackets so as to permit

free expansion and contraction. Risers are to be supported at each floor with

galvanized steel clamps. To permit free movement of common piping support

are from a common hanger bar fabricated from galvanized steel sections.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

Pipe hangers are provided at the following maximum spacing:

Pipe Dia (mm) Hanger Rod Dia Spacing between Supports

The end of the steel rods are threaded and not welded to the threaded bolt.

Pipe sleeves, larger diameter than pipes, are provided wherever pipes pass

through walls and slab and annular space filled with fiberglass and finished

with retainer rings.

Automatic air valves are provided at all high points in the piping system for

venting. All valves are of 15mm pipe size and are associated with an equal

size gate valve.

Discharge from the air valves are piped through a pipe to the nearest drain or

sump. All pipes are pitched towards drain points.

2.3. Air Vessel

The air vessel are provided to compensate for slight loss of pressure in the

system and to provide an air cushion for counter-acting pressure, surges,

whenever the pumping sets come into operation. Air vessel is conform to

MNDF. It is normally half full of water, when the system is in normal

operation. Air vessel is fabricated with 8 mm thick M.S. plate with dished ends

and suitable supporting legs. It is provided with one 100 mm diameter flanged

connection from pump, one 25 mm drain with valve, one water level gauge

and 25 mm sockets for pressure switches. The air vessel is tested to pressure

for 12 hours at 2 times the operating pressure or 1.5 times the shut-off.

2.4.1 Sluice Valves

Sluice valves are double flanged valves with cast iron body. The spindle, wall

seat and wedge nuts are of bronze. They are generally having non-rising

Sluice valves are conforming to MNDF.

2.4.2 Butterfly Valve

The butterfly valve is suitable for waterworks and rated for 300 P.S.I

The body is of cast iron conforming to MNDF in circular shape and of high

strength to take the water pressure. The disc is heavy duty cast iron with anti-

corrosive epoxy or nickel coating.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

The valve seat is of high-grade elastomer or nitrile rubber. The valve in closed

position has complete contact between the seat and the disc throughout the

perimeter. The elastomer rubber has a long life and not give away on

continuous applied water pressure. The shaft is EN 8 grade carbon steel.

The valve is to be fitted between two flanges on either side of pipe flanges.

The valve edge rubber is projected outside such that they are wedged within

the pipe flanges to prevent leakages.

2.4.3 Ball Valve

The ball valve is made of forged brass and suitable for test pressure of pipe

line. The valve is internally threaded to receive pipe connections.

The ball is made from brass and machined to perfect round shape and

subsequently chrome plated. The seat of the valve body-bonnet gasket and

gland packing is of Teflon.

The handle is provided with PVC jacket. The handle also indicates the direction

of ‘open’ and ‘closed’ situations. The gap between the ball and the Teflon

packing is sealed to prevent water seeping.

The handle also be provided with a lug to keep the movement of the ball valve

within 90°. The lever is operated smoothly and without application of any

unnecessary force.

2.4.4 Gun Metal Valves

Gun metal Valves are used for smaller diameter pipes, and for threaded

connections. The Valves are bear certification in accordance with MNDF.

The body and bonnet are of gun metal conforming to MNDF. The stem gland

and gland nut are of forged brass conforming to MNDF. The hand wheel is of

cast iron conforming to MNDF.

The hand wheel is of high-quality finish to avoid hand abrasions. Movement is

also be easy. The spindle is non-rising type.

2.4.5 Non-Return Valve

Non-return valves are cast iron double flanged with cast iron body and

gunmetal internal parts conforming to MNDF.

2.5. Pressure Switch

The pressure switches are employed for starting and shutting down operation

of pumps automatically, dictated by line pressure. The pressure switch is

diaphragm type. The housing is die cast aluminium, with SS 316 movement,

pressure element and socket. The set pressure is adjustable.

The Switch is suitable for consistent and repeated operations without change

in values. It is provided with IP: 55 water and environment protection.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

2.6. Pressure Gauge

Pressure gauge is provided near all individual connections of the hydrant

system with isolation valves and near each flow switch assembly of the

sprinkler system. Pressure gauge is 50 mm dia gunmetal bourdon type with

gunmetal isolation ball valve, tapping and connecting pipe and nipple. The

gauge is installed at appropriate height for easy readability.

All hydrant pipes shall be painted with post office red color paint. All G.I. pipes

are first be cleaned thoroughly before application of primer coat. After

application of primer coat two coats of enamel paint is to be applied. Nuts and

bolts are painted black, while valves are painted blue.

2.8. Fire Hydrants

2.8.1 Internal Hydrants

• Each internal fire hydrant station is consisting of two numbers of 63 mm

dia. 15 m long rubberized fabric lined hose pipes with gunmetal male and

female instantaneous type coupling machine wound with GI wire, fire hose

reel, gunmetal branch pipe with nozzle as per MNDF requirement.

• Standard fire hose reels of 19mm diameter high pressure Dunlop rubber

hose 30 m long with gunmetal nozzle, all mounted on a circular hose reel

of heavy duty mild steel construction having cast iron brackets are also to

be provided. Hose reel is connected directly to the wet riser with an

isolating valve. Hose reel is conforming to MNDF and is mounted vertically.

• Each internal hydrant hose cabinet is to be provided with a drain in the

bottom plate. The drain point leads away to the nearest general drain.

• Each internal hydrant hose cabinet is also be provided with a nozzle

spanner and a fireman’s axe.

• Each hose cabinet is conspicuously painted with the letters “FIRE HOSE”.

2.9. Hose Reel

Recess Hose reels approved to BS EN 671-1: 1995, or any other equable

International Standard, Automatic operation, Right or Left hand take off.

Including 30m length of Hose, 19mm diameter Hose approved to PR EN 694,

or any other equable International Standard, and Nylon twist operated

Jet/spray Nozzle on mounting plate with integral flexi guide for Hose

withdrawal device. 03 or 04 fixing holes shall be provided in position indicated

to suit M8/M10 sized fixing screws or M12 fixing bolts. With Ball valve inlet

and Flexible inlet water Pipe.

The Hose Reels and the related equipment’s are to be approved by the MNDF

Fire and Rescue Service before Installation. Special permission is to be taken

for the other size of the Hose reels.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

The Hose Reels nozzle retainer or hose guide and the inlet valve should be

fitted at a height of about 900mm above floor level.

2.10. Fire Hose

All hose pipes are of 63 mm diameter RRL/ CP as required, conforming to

MNDF. The hose is provided with copper alloy delivery coupling. The hose is

capable of withstanding a bursting pressure of 35.7 Kg/Sq.cm without undue

leakage or sweating. Hose is provided with instantaneous spring-lock, type

2.11. Branch Pipe, Nozzle

Branch pipes are of gun metal with loaded tin bronze ring at the discharge and

to receive the nozzle and provided at the other with a leaded tin bronze ring

to fit into the instantaneous coupling. Nozzle is of spray type of diameter of

not less than 16 mm and not more than 25 mm. Nozzle is of loaded tin bronze

branch pipe and nozzle is of instantaneous pattern conforming to MNDF.

2.12. Hose Cabinet

Hose cabinet is provided for all internal and external fire hydrants. Hose

cabinets are fabricated from 16 gauge MS powder coated sheet of fully welded

construction with hinged double front door partially glazed (3 mm glass panel)

with locking arrangement, stove enameled fire red paint (shade No. 536 of

IS:5) with “FIRE HOSE” written on it prominently. Cabinet surfaces in contact

with the walls are not be powder coated but instead given two coats of anti-

corrosive bit mastic paint.

2.13. Internal Hose Cabinet

Hose cabinet is of glass fronted with hinged door and lock. The cabinet is

made of 16-gauge thick MS sheet and spray painted to shade No. 536 of IS:5.

The hose cabinet is of size to accommodate the following:

• Landing valves (Single headed)

• Hose reel (30 mtr.)

• Branch pipes, nozzles (2 sets)

• Fire man's axe and hand appliances

2.14 Fire Protection System

• Check all hydrant valves by opening and closing: any valve found to be

open is to be closed.

• Check all the piping under hydro test.

• Check that all suction and delivery connections are properly made for

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of

Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

• Check rotation of each motor after decoupling and correct the same if

• Test run each pump set.

• All pump sets shall run continuously for 8 hours (if required with

temporary piping back to the tank).

• Pressurize the fire hydrant system by running the jockey pump and

after it attains the shutoff pressure of the pump, then

• Open bypass valve and allow the pressure to drop in the system. Check

that the jockey pump cuts-in and cuts-out at the preset pressure. If

necessary, adjust the pressure switch for the jockey pump. Close by-

• Open hydrant valve and allow the water to below into the fire water

tank in order to avoid wastage of water. The main fire pump is cut-in at

the preset pressure and is not cutout automatically on reaching the

normal line pressure. The main fire pump is stop only by manual push

button. However, the jockey pump is cut-out as soon as the main pump

• Switch off the main fire pump and test check the diesel engine driven

pump in the same manner as the electrically driven pump,

• When the fire pumps have been checked for satisfactory working on

automatic controls, open fire hydrant valves simultaneously and allow

the hose pipes to discharge water into the fire tank to avoid wastage.

• Check each landing valve, male and female couplings and branch pipes,

for compatibility with each other. Each landing valve is also be checked

by opening and closing under pressure.

• Check all annunciations by simulating the alarm conditions at site.

• Start the sprinkler pump and develop the required pressure in the

sprinkler pipes.

• Open the test valve to test the automatic starting of the pump. If

necessary, make necessary adjustments in the setting of pressure

switch. The sprinkler water gong

• alarm is also operate when the test valve is open. This operation is to

be done for each and every section of the sprinkler system and the

alarm for each section (via flow switch) is checked for operation.

• After satisfactory operation of the pump the Tenderer is set up mock

fire and test the system.

• Check all annunciations by simulating the alarm conditions at site.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,

Republic of Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

TECHNICAL SPECIFICATIONS

ELECTRICAL SYSTEM

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,

Republic of Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

1. Scope of Work of the Electrical Works

The Scope of work includes supply, installation, testing, commissioning

and handing over the entire electrical system, As-Built drawings and O &

M manuals along with necessary test certificates as required.

The works involves as follows –

(a) Internal Electrical Installation with switch, sockets & wiring etc. The

Lighting fixtures and fans will be provided as follows :

i) Housing Units - Lighting Fixtures and Ceiling

ii) Common areas, services - Lighting Fixtures, Ceiling Fans,

areas i.e. Electrical Exhaust Fans

Rooms, Pump Rooms etc.

(b) The Exit Lights to be provided as per the codal and local by-laws

requirements applicable.

(c) No Exhaust Fans, Bell buzzer, Geyser, TV and Telephone

instruments, ONT etc. to be provided inside the flats.

(d) Distribution Boards

(e) Elevators (3 nos. per tower as per specifications)

(f) Fire Detection & Alarm System (Conventional type-Manual)

(g) Lightning Protection System (Conventional type)

(h) Main Distribution Board of Tower with incoming cables from Sub

Station, laying and termination at both ends.

(i) Meter Boards Enclosures with Meters as approved by Local

Statutory body i.e. M/s STELCO

(j) Common area Panel for Lighting and Power Panel for Residential

with incoming cables and termination at both ends

(k) Common area Panel for Lighting and Power Panel for Commercial

with incoming cables and termination at both ends

(l) Lift panels with incoming cable and outgoing cables with

terminations at both ends

(m) Fire Fighting Panel with incoming cable and outgoing cables with

terminations at both ends.

(n) Incoming cable with terminations at both ends for Plumbing Panel

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,

Republic of Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

(o) Earthing System

(p) LT Cables & Cable Tray

(q) Safety Equipment.

(r) Conduiting for ELV systems such as CCTV, GPON System , Access

Control System, data / voice networking, antennas etc.

(s) Obtaining necessary statutory approvals from concern authorities

i.e. electricity authorities etc.

(t) 415V, 3 Phase, 4 wires, 50 Hz Incoming supply will be received in

the Main Distribution Board of the Tower placed in the panel room

at Ground Floor.

(u) The Meter Boards (approx. 8 nos. per tower each suitable for

accommodating approx. 20 nos. meters) are provided with lockable

cubicle for individual separate meter of each Dwelling unit.

(v) The single point Electrical Supply to the Main Distribution Board of

the each Tower will be taken from the Sub Station, further all

distribution will be done inside the tower.

(w) The connections from the meter boards to the Flat distribution

Boards and Common area Panel to the common area light & power

DBs i.e. staircase DBs ,corridors & lift lobby area light & power DBs

will be done through sub main wiring in conduit. The conduits from

the panels to the shafts to be laid on the cable tray and in the

shafts on the cable tray /MS supports as per approved design.

(x) In the common areas DBs to be provided

(y) On the floors the concealed conduit from shafts to the distribution

Boards inside the Dwelling unit to be used

(z) To all Dwelling units 1-ph, 2W, 220V, 50HZ Electrical supply to be

provided. SPN Lighting + Power DB will be provided in the each flat.

(aa) Only 13A universal and 15A, 3-Pin round sockets to be used.

(bb) The circuits for Lights & Fans, 13A Sockets and 15A Sockets will be

(cc) The Sizes of the wires shall as follows –

(i) Lights, Fans and call bell : 2x1.5 + 1x1.5 Sqmm Cu

(ii) 13A Universal sockets : 2x2.5 + 1x2.5 Sqmm Cu

(iii) 15A Sockets : 2x4.0 + 1x4.0 Sqmm Cu

(dd) The maximum points which can be connected in a circuits –

(i) Lights, Fans and call bell : Five (5) Nos.

(ii) 13A Universal sockets : Two (2) Nos.

(iii) 15A Sockets : Two (2) Nos.

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,

Republic of Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

(ee) The sub main sizes as follows:

(i) 2 BHK : 2x16.0 + 1x6.0 Sqmm Cu

(ff) Emergency Lights for all common areas, service rooms and escape

routes to be provided.

(gg) Self-contained Exit Sign with standby batteries and automatic

charging facility to be provided.

(hh) Codes and Standards to be Followed –

(i) State Electric Company Ltd (STELCO) – Energy and Power

(ii) Maldives Energy Authority (MEA)

(iii) Relevant Telecom and Internet Service Provider

(iv) Maldives National Defence Force (MNDF) – Fire Protection

(v) Ministry of Environment & Energy (if relevant)

(vi) Ministry of Health (if relevant)

(vii) International Codes & Standards

(viii) National Fire Protection Association (NFPA)

2. Internal Electrification

2.1 Electrical Wiring

2.1.1 Electrical wiring should be done by a MEA approved and

licensed electrician.

• Wiring color code:

o In single phase wiring, the phase wire must be brown, neutral must

be blue, and the earth must be green with yellow stripes.

o In three phase wiring, phase 1 must be black, phase 2 must be

brown, phase 3 must be grey, neutral must be blue, and the earth

must be green with yellow stripes.

o In any case, for earth wire anything other than green with yellow

stripes and for neutral anything other than blue must not be used

o As a temporary measure, for as long as the MEA authorizes it, at

sites where three phase wiring is required, and the prescribed color

of wire is not available, the end of each wire should be sleeved with

the respective phase color.

• In three-phase wiring the load should be balanced among the three

• Phase wires are dimensioned to withstand in normal operation the

aggregated current of the loads there connected. The licensed

engineer or electrician (whereas applicable) certifies dimensions of

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,

Republic of Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

• The typical tripping current for earth leakage circuit breaker in

households or residential buildings are 30 milli Amps. Nevertheless,

it is possible to set the tripping point to different current levels where

deemed necessary. The circuit breaker is 240 V rated voltage and

30-63 Amps rated current, 2 pole current operated ELCB. In case of

three phase circuits, for a tripping current of 30 milli Amps, the

circuit breaker is 30-63 A rated current, 380-400 rated voltage and 4

pole current operated. The rated current did not exceed the

prescribed level and the tripping current must not exceed 30 milli

Amps. ELCB with tripping currents less than 30mA can be accepted

where it is deemed necessary. Exception to this rule are ELCB of

residual current devices installed in central alternative current

systems of buildings which may have trigger current higher than 30

milli Amps but in any case not exceeding 100 milli Amps.

• For a light circuit, if the wire size is 1.5 mm2 a single circuit must not

exceed a total of 1000W.

• Not more than one phase must be used in a single box

• Wiring must be done in a conduit or trunking.

• Machineries installed in commercial and industrial electrical

installations must be connected by using appropriate cable size and

through starter or main switch. Such starter switch must be installed

close to the machinery in an easy to operate manner.

• Water prone areas should have water proof switches and socket

outlets. if normal switches & sockets are is used, it must be mounted

where water will not reach it.

• Any type of socket can be installed but at least one socket per room

is of Type G BS-1363.

• Insulation resistance of an installation (phase-neutral, phase-earth

and neutral-earth) should have minimum of 1 mega ohms.

• In case a resident needs to connect a backup/emergency generator

apart from the existing service provider’s supply a change-over

switch must be introduced. The change-over switch must be able to

disconnect the phase/live conductors and as well as the neutral, and

must present a rating adequate to the required load.

• All new electrical installations are tested and approved by either

licensed engineers or electricians (according to the case) for such

purposes, before being energized and will be accountable if any fault

arises from the distribution board wiring.

2.1.2 Selection and erection in relation to external influences

• The wiring system is selected and erected so as to be suitable for the

highest local ambient temperature.

• Wiring system components including cables and wiring accessories

are installed or handled only at temperature within the limits

stated in the relevant product specification or as given by the

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,

Republic of Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

• In order to avoid the effects of heat from external sources one of the

following methods or an equally method is used to protect wiring

o Placing sufficiently far from the sources of heat;

o Selecting a system with due regard for the additional

temperature rise which may occur; or

o Local reinforcement or substitution of insulating material.

• The wiring system is selected and erected so that no damage is

caused by ingress of water. The completed wiring system complies

with the IP degree of protection relevant to the particular location.

• Where water may collect or condensation may form in wiring system,

provision is made for its escape.

• Where wiring system may be subjected to waves, protection against

mechanical damage is afforded.

• Wiring system is selected and erected so as to minimize the danger

arising from the ingress of solid foreign bodies. The completed wiring

system complies with the IP degree of protection relevant to the

particular location.

• In a location where dust in significant quantity is present, additional

precaution is taken to prevent the accumulation of dust or other

substances in quantities which could adversely affect the heat

dissipation from the wiring system.

• Where the presence of corrosive or pollution substances, including

water, is likely to give rise to corrosion or deterioration, parts of the

wiring system likely to be affected is suitably protected or

manufactured form a material resistant to such substances.

• Dissimilar metals liable to initiate electrolytic action are not placed in

contact with each other, unless special arrangements are made to

avoid the consequences of such contacts.

• Material liable to cause mutual or individual deterioration or

hazardous degradation is not placed in contact with each other.

• The wiring system is selected and erected so as to minimize the

damage arising from mechanical stress, e.g. by impact, penetration

or compression.

• In installations fixed to a structure or equipment, fixation is afforded

Signature of Contractor NBCC

Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,

Republic of Maldives (Package-I)

Technical Specifications- Revised as per Corrigendum – Addendum 03

o The mechanical characteristics of the wiring system; or

o The location selected; or

o The provision of additional local or general mechanical protection;

o By any combination of the above.

• The wiring system supported by or fixed to structure of equipment

subject to vibration of medium severity or high severity is suitable for

such conditions, particularly where cables and cable connection are

• The wiring system is selected and erected so as to prevent during

installation, use or maintenance, damage to sheath and insulation of

cables and conductor and their terminations.

• When buried in the structure, conduits or cable ducting system is

completely erected for each circuit before any insulated conductor or

cable is drawn in.

• The radius of every bend in a wiring system complies with the

minimum bending radius recommended by the cable or wire

• Where the conductors and cables are not supported continuously by

their supports or due to the method of the installation, they are

supported by suitable means at appropriate intervals in such a

manner that the conductors and cables do not suffer damage by their

• Where a permanent tensile stress is applied to the wiring system

(e.g. by its own weight in vertical runs) a suitable type of cable or

conductor with appropriate cross- sectional areas and method of

mounting is selected, in such a manner that the conductors and

cables do not suffer damage by their own weight.

• Wiring system intended for the drawing in or out of conductors or

cables has adequate means of access to allow this operation.

• Wiring system buried in floors are sufficiently protected to prevent

damage caused by the intended use of the floor.

• Wiring system which are rigidly fixed and buried in the walls are run

horizontally or vertically or parallel to the room edges.

• Wiring system is installed so that excessive tensile stress to the

conductors and connections is avoided.

• Flexible wiring system is installed so that excessive tensile

stress to the conductors and connection is avoided.

• Where the conditions experienced or expected constitute a hazard