Public Works Department Tender

Dismantling asbestos sheet roofing including ridges, hips valley and gutters and stacking the material within 50 meters lead.

Providing & Fixing in position Double Skin roof with Zincalume/ Galvalume colour coated & bare profile sheet with subtle square fluting factory cut at all heights for roof, side & Gable cladding complete in all respect. TOP SHEET-The end rib shall be designed for anti-capillary action. The feed material should be manufactured out of nominal 0.45 mm Base Metal Thickness (BMT), Hi-strength steel with min. 550 MPa yield strength, metallic hot dip coated with Aluminium-Zinc alloy (55% Aluminium, 43.5% Zinc &1.5% Si) as per AS 1397 - Zincalume AZ150 (Min. 150 gms/sq.mt total on both sides) with quality paint coat as per AS/NZS 2728 type 3-4. The paint shall have a total coating thickness of nominal 35 μm, comprising of nominal 20 μm exterior SMP coat on top surface and nominal 5 μm reverse backer coat on back surface over nominal 5 μm primer coat on both surfaces of approved colour shade. Total Coated Thickness (TCT) should be 0.50mm. Total Painted Thickness (TPT) should be in addition to 0.50mm. The steel sheet shall be fastened with nominal 40 μm zinc coated or nominal 25 μm zinc-tin alloy coated, Hex head, self-drilling screw as per AS 3566-2002 Class 3 fasteners of approved make with EPDM washer as per the requirement considering the profile shape and design load. The fastener size shall be calculated as per the design or manufacturers recommendations.

The profile sheet, fastener size etc. shall be approved by the Engineer. The sheeting should be with minimum 200mm lap & waterproof with Silicon sealant non-hardening neutral cure type shall be applied at all end laps, complete as directed Z-Sub Girt - roll formed section 50x50x50x1.50 TCT, 120GSM Galvanised, High Strength (345 MPa), approximate Wt. 1.85 kg/r.m. fixed with self tapping screws Glass Wool Insulation with FSK facing 50mm with 24 kg/m3 density in between 2 sheets. LINER SHEET-bare galvalume/zincalume roofing sheet of same profile as top sheet. The feed material is of manufactured out of nominal 0.45 mm Base Metal Thickness (BMT) (0.47 mm TCT), Hi-strength steel with min. 550 MPa yield strength, metallic hot dip coated with Aluminium-Zinc alloy (55% Aluminium, 45% Zinc) as per AS 1397 - Zincalume AZ150 (Min. 150 gms/sq.mt total on both sides), passivated & resin coated. The feed material should have coil manufacturer’s product details marked at regular interval for confirming genuinity of the material. complete as per the directions of the engineer. The steel manufacturer's test certificate for the chemical & mechanical properties of steel must be submitted for approval prior to installation.