Providing and laying of water proofing treatment over roof of New Guest House Building and Hospital Building at THP Colony MPPGCL Sirmour.

SOR Item No.- 14.1 - Repairs to plaster of thickness 12mm to 20mm in patches of area 2.5 sq. metres and under including cutting the patch in proper shape, raking out joints and preparing and plastering the surface of the walls complete including disposal of rubbish to the dumping ground within 50metres lead : With cement mortar 1:4 (1 cement : 4sand).

SOR Item No.- 22.23 -Providing waterproofing treatment over roof, walls, chhajjas and balconies with a rubberized elastomeric cold-applied liquid waterproofing membrane, comprising a special resin and rubber blend having more than 1300% elongation, conforming to ASTM D2370-98, at leakage/seepage areas, including the following operations: (i) Removal of existing damaged waterproofing treatment: Removal of damaged/existing waterproofing treatment, if any, such as bituminous membrane, plaster, brick-bat coba, screeding, etc. (ii) Surface preparation and repairs: Thorough preparation of the surface by roughening/scrubbing with a steel wire/nylon brush, removal of all dust and loose particles, and washing with adequate water to ensure complete cleaning. Cracks shall be opened in V-groove of size 5 mm × 10 mm (W × D) and filled with elastomeric crack filler/PU sealant. Potholes and holes in the roof surface shall be repaired with polymer mortar using SBR bonding agent. (iii) Application of primer and reinforcement: Providing and applying the 1st coat of rubberized elastomeric liquid membrane as primer, in the ratio of 1 part liquid membrane to 2 parts water, by brush/roller/spray, achieving a minimum thickness of 70–80 microns. The coating shall be allowed to set naturally in air for a minimum of 2 hours. Thereafter, 45 GSM fibre glass mesh shall be laid as reinforcement and the 2nd coat of rubberized elastomeric liquid membrane shall be applied in the ratio of 1 part membrane to 20% water, achieving a minimum thickness of 100–120 microns. The coating shall be allowed to set naturally in air for a minimum of 12 hours. (iv) Third coat: Providing and applying the 3rd coat of rubberized elastomeric liquid membrane in the ratio of 1 part membrane to 10% water. The total Dry Film Thickness (DFT) after completion of all three coats shall be 280–300 microns, with an average consumption of 6.5 kg per 10 sqm. (v) Fourth and fifth coats: Providing and applying the 4th and 5th coats of high-quality waterproof membrane in white colour, consisting of a single-component, special synthetic-resin-based, flexible thixotropic white-colour coating having excellent UV resistance (SRI-144) and more than 300% elongation, conforming to ASTM D412-98. The material shall be applied in the ratio of 1 part membrane to 10% water, achieving a total DFT of 200 microns in two coats, with an average consumption of 5 kg per 10 sqm. After application of the 4th coat, the surface shall be allowed to air-dry for a minimum of 3 hours before application of the 5th coat. (vi) Water-tightness test: The treated area shall be tested for leakage/seepage by flooding with water for a minimum period of 48 hours. (vii) Authorized applicator: The complete membrane coating application shall be carried out through an authorized applicator of the manufacturer. (viii) Service guarantee: A 5-year service guarantee shall be provided by the contractor/manufacturer, as applicable. All the above operations shall be carried out in the prescribed sequence and strictly as per the instructions and directions of the Engineer-in-Charge.