Special Repair to Roof

Dismantling existing Mangalore tiled roofing including carefully removing and stacking serviceable Mangalore tiles for reuse, disposal of unserviceable tiles within 50-metre lead, exposing battens, rafters and purlins for inspection and subsequent repairs, complete as per CPWD Specifications and directions of Engineer-in-Charge.

Dismantling roofing including ridges, hips, valleys and gutters etc., and stacking the material within 50 metres lead of: G.S. Sheet complete as per CPWD Specifications and directions of Engineer-in-Charge.

Re-laying serviceable Mangalore tiles recovered from dismantled roof over GI sheet placed upon existing/new wooden battens and rafters including cleaning, sorting, fixing with GI nails/hooks, replacing broken tiles, alignment, overlaps and making roof watertight complete as directed by Engineer-in-Charge.

Providing and fixing new Mangalore tiles (Class AA conforming to IS 654) on wooden battens and rafters including GI nails and accessories complete as per CPWD specifications and as per direction of Engineer-in-Charge.

Providing and fixing factory made pre-painted galvanised iron rainwater gutter fabricated from 0.63 mm thick galvanised steel sheet with zinc coating not less than 120 gsm, of approved profile and size, including bending, shaping, joining, end caps, outlets, gutter brackets/supports at suitable spacing, nuts, bolts, screws, sealant, cutting, drilling and fixing to timber/steel roof members complete as per manufacturer's specifications and directions of Engineer-in-Charge. The work shall include all necessary accessories and fittings required for proper collection and conveyance of rainwater from the Mangalore tiled roof and making the entire gutter system leak-proof and functional.

Providing and fixing pre-coated galvanized iron profile sheets of approved profile and thickness 0.50 mm (0.45 mm BMT) with zinc coating 120 gsm, complete with self-drilling/self-tapping screws and EPDM washers, laid over timber battens/purlins as a continuous waterproof underlayer below Mangalore tiled roofing including side laps, end laps, cutting to shape, dressing around ridges, hips, valleys, junctions and all incidental works complete as per CPWD Specifications and directions of Engineer-in-Charge.

Providing and fixing matching Mangalore ridge and hip tiles over roof ridges, hips, junctions and ancillary roof portions including bedding in cement mortar, pointing, curing and all incidental works complete as per CPWD Specifications and directions of Engineer-in-Charge. The pre-coated GI sheet underlayer provided below the Mangalore tiled roofing shall be suitably lapped, dressed and extended beneath the ridge and hip tile locations to ensure continuity of waterproofing and complete watertightness of the roof system. The work shall include proper alignment, finishing and making all ridge, hip and junction portions fully watertight, as per CPWD specification and direction of Engineer-in-charge.

Providing and fixing pre-coated galvanised steel sheet flashings, aprons and roofing accessories of total coated thickness not less than 0.50 mm (including 0.45 mm base metal thickness) and GI flashing of 0.63 mm thickness at roof-wall junctions and around existing roof ventilators, including cutting grooves in masonry, cutting, bending, dressing, embedding flashings in grooves, making side laps and end laps, fixing with self-drilling screws, sealing all joints and grooves with approved polymer sealant, making good the masonry after fixing, and ensuring complete watertightness of roof-wall junctions, ventilator peripheries and all associated locations, complete in all respects as per CPWD Specifications and as directed by the Engineer-in-Charge.

Filling gaps and junctions between pre-coated GI ventilator flashing and adjoining roof ventilator assembly by providing approved weather resistant non-sag elastomeric PU sealant over suitable backing, including cleaning, preparation of surfaces and complete sealing to make ventilator junctions watertight, complete as per CPWD Specifications and directions of Engineer-in-Charge.

Cleaning and preparing exposed Mangalore tiled roofing surface including removal of moss, dirt and loose particles and applying approved exterior grade acrylic coating of required shade on new and relaid Mangalore tiles for improving durability, appearance and resistance against weathering complete.