Waterproofing Treatment of Roof of Geomagnetic Observatory Instrument Room and Horticulture Section at CSIR-NGRI, Hyderabad

Description of Items :

Providing and laying APP (Atactic Polypropylene Polymer) modified prefabricated five layer 3 mm thick water proofing membrane make of Leaksheild or equivalent, black finished reinforced with non-woven polyester matt consisting of a coat of bitumen primer for bitumen membrane @ 0.40 litre/sqm by the same membrane manufacture of density at 25°C, 0.87-0.89 kg/litre and viscocity 70-160 cps. 2nd and 4th coat of bonding material @ 1.2 Kg/Sqm, which shall consist of blown type bitumen of grade 85/25 conforming to IS 702 (Over the primer coat providing and applying a bitumin coat shall be applied i.e 2nd coat.) After the bitumin coat the layer of membrane shall be laid using Butane Torch and sealing all joints etc, and preparing the surface complete.(After laying APP sheet, providing and applying a bitumen coat shall be applied on the top surface of APP sheet i.e 4th coat.) The vital physical and chemical parameters of the membrane shall be as under : Joint strength in longitudinal and transverse direction at 23°C as 650/450N/5cm. Tear strength in longitudinal and transverse direction as 300/250N. Softening point of membrane not less than 150°C. Cold flexibility shall be upto -2°C when tested in accordance with ASTM, D - 5147. The laying of membrane shall be got done through the authorised applicator of the manufacturer of membrane :(a) Guarantee Bond to be furnished for 10 years warranty .(b) Provision of Pond test:- The contractor / applicator have to provide for the pond test on the terrace after the completion of sealing of joints for 72 hours. The water level will be a minimum depth of 100 mm at the junction of terrace and parapet wall i.e. the highest point on the terrace.

Removing of old waterproofing sheet/tarfelt/membrane by using manpower/mechnical/removing or rubbing with soaked cotton to complete removing and disposed the unserviceable materials out the camps.

Finishing the waterproofing treatment with a coat of solar reflecting Bituminous Aluminum paint @ 150 gms/sqm.

MADHURI CONSTRUCTIONS