Waterproofing of roof terraces at CIAB Lab building, Knowledge City, Sector-81, Mohali

Providing and applying complete rooftop waterproofing treatment on existing RCC roof/terrace slabs of buildings, including thorough inspection of the roof surface; removal of vegetation, debris, dust, dirt, algae, moss, grease, oil deposits and all foreign materials; mechanical wire brushing, grinding and scarification of the surface wherever required; removal of loose, unsound, deteriorated concrete, old waterproofing layers and defective mortar inculding dispoal in low lying area of the same; preparation of sound substrate suitable for waterproofing treatment; washing and drying of the surface.The work shall include repair of cracks by V-grooving, cleaning and filling with approved polymer-modified cementitious repair mortar; repair of honeycombs, surface depressions and damaged concrete using polymer-modified repair mortar; treatment of cold joints, construction joints and expansion joints using approved elastomeric joint sealant and compatible waterproof joint treatment system; providing 75 mm × 75 mm polymer-modified cement mortar angle fillets at all wall-floor junctions, parapet junctions, upstands, kerbs, equipment foundations and similar locations. The item shall further include waterproof sealing around AHU bases, Stone cladding/flooring, HVAC equipment supports, pipe penetrations, sleeves, conduits, cable trays, service entries, rainwater outlets, drain mouths, overflow pipes and all critical vulnerable locations, ensuring complete watertight treatment using compatible waterproofing accessories, sealants and reinforcing materials as recommended by the manufacturer. After completion of repairs, the surface shall be treated with a compatible waterproofing primer. The waterproofing system shall consist of application of first coat of high-performance elastomeric waterproofing coating, followed by providing and embedding alkali-resistant glass fiber mesh reinforcement over the entire roof surface, with minimum 100 mm overlap at joints and complete embedding in the wet coating. Thereafter, application of second elastomeric waterproofing coat shall be carried out ensuring complete encapsulation of the reinforcing mesh and achievement of the required dry film thickness. A final UV-resistant protective waterproof coating shall then be applied uniformly to provide resistance against ultraviolet radiation, weathering, thermal cycling and long-term water exposure. The work shall include all materials, labour, skilled and unskilled manpower, mixing, application, curing, tools and tackles, machinery, scaffolding, staging, safety measures, protection of adjacent works, transportation, loading, unloading, storage, handling, wastage, testing, quality control, finishing, cleaning of the site and all incidental works required for proper execution. After completion of the waterproofing treatment, the contractor shall conduct a 48 to 72 hours ponding test over the treated roof area in the presence of the Engineer-in-Charge. Any leakage, seepage or defect observed during the testing period shall be rectified by the contractor at no extra cost, and the test shall be repeated until satisfactory performance is achieved. The work shall be completed strictly in accordance with the manufacturer’s specifications, technical data sheets, written recommendations and the directions of the Engineer-in-Charge. The waterproofing system shall be executed using approved products of Sika / Fosroc / Mapei (Mapai) make, including primer, repair mortar, reinforcing mesh, elastomeric waterproof coating, UV protective coating, sealants and accessories, and shall carry a minimum 7 (seven) years written performance warranty jointly by the manufacturer and the applicator against leakage and seepage, complete in all respects.

Providing and carrying out watertight sealing treatment around AHU (Air Handling Unit) duct/pipe penetrations through brick masonry/RCC shaft walls, including cleaning of the entire area and removal of dust, dirt, loose mortar, deteriorated material, laitance, oil, grease and all foreign matter; cutting/chasing grooves around the duct/pipe periphery wherever required to obtain a sound substrate; widening and cleaning of cracks, joints and gaps; and preparation of the surface suitable for waterproof sealing treatment. The work shall include filling all gaps, annular spaces and joints between AHU ducts/pipes and surrounding brickwork/RCC with approved polyurethane (PU) or hybrid elastomeric waterproof sealant, providing closed-cell polyethylene backing rod of appropriate diameter wherever required to maintain the required sealant depth and profile, and application of compatible primer on masonry, concrete and metal surfaces prior to sealant application, as recommended by the manufacturer. The item shall further include reinforcement of critical locations with non-woven polyester/fiber reinforcement mesh embedded in a compatible waterproofing coating/sealant system around the penetration zone to prevent cracking and water ingress due to thermal movement and vibration. The sealant shall be neatly tooled and finished to form a continuous flexible watertight barrier around the entire perimeter of the AHU duct/pipe penetration. The treatment shall ensure that no water leakage or seepage occurs around AHU ducts, chilled water pipes, refrigerant lines, sleeves, conduits, cable entries or associated service penetrations, and shall be suitable for long-term resistance against weathering, moisture ingress, thermal expansion/contraction and vibration. The work shall include all materials, labour, skilled and unskilled manpower, tools and tackles, equipment, scaffolding/staging (if required), surface preparation, chasing, cleaning, priming, sealant application, reinforcement, curing, testing, quality control, transportation, loading, unloading, storage, handling, wastage, protection of adjacent works, finishing, disposal of debris in low lying area and all incidental works necessary for satisfactory completion of the work, complete as per the manufacturer’s specifications and the directions of the Engineer-in-Charge. The sealing system shall be executed using approved products of Sika / Fosroc / Mapei (Mapai) make and shall provide a durable watertight seal around AHU duct/pipe penetrations, complete in all respects.