Installation of metal profiled sheet around the parapet wall of existing colony quarters at ERPL, Madarihat.

Designing, providing, fabricating and fixing profiled sheeting 730-1020 mm cover width, 28-30 mm crests @ 186-333 mm centre to centre, manufactured out of 0.45 mm BMT (Base Metal Thickness) Hi-Tensile Steel (Minimum yield strength of 550 MPa) coated with hot dip metalic galvalume/ zincalume coating AZ-150 or equivalent as per AS:1397 and super polyster XRW quality paint coat as per AS/ NZS2728 (Category-3) of approved colour for roofing, cladding, gutters, rainwater pipes, spouts etc. The total mass of the coating on both sides shall be 150 gms/sqm (Zinc 45%/ Aluminium 55%). The total paint coat thickness shall be 35 microns, comprising of 20 microns exterior coat of super polyster XRW on top surface and 5 micron super polyester on back surface over 5 micron primer coats on both surfaces including side and end laps. The sheets shall have wide pans with 2-3 stiffening ribs for effective water shedding and special male/ female ends with full return legs on side laps for purlins support and anti-capilary flute in side lap. The sheets shall be fixed using polymer coated hot dip galvanised hex head self drilling fasteners as per AS:3566 (Class-3) on each crest of sheets for connection with purlins and polymer coated hot dipped stitching fasteners at 300 mm c/c on all sides and end laps, etc. Approved sealing tapes shall be used on side laps and end laps of sheets and closer to be provided at the last end of sheet. The measurement shall be based on per unit of finished/ laid area. Item to include curved sheets also wherever required. The Contractor shall give minimum 10 year guarantee for the sheets against deterioration, disintegration, loss of lustre, variation in colour, etc. and leakages across laps, fasteners etc. The Contractor is to submit design and shop drawing for approval on the sheet profile, design and details before installation :

Roof, side cladding, gable end cladding, gutters, rainwater pipes/ spouts etc. [Note: The area of sheet coverings shall be measured on the flat surface i.e. without allowance for laps and ribs]

Providing and fixing carbon steel galvanised (minimum coating 5 micron) dash fastener of 10 mm dia. double threaded 6.8 Grade (Yield Strength 480 N/sq.mm.), counter sunk head, comprising of 10 mm dia. Polyamide PA 6 Grade sleeve, including drilling of hole in frame , concrete/ masonry, etc. as per the directions of Engineer-in-Charge :

10x60 mm

Structural steel work riveted, bolted or welded in built up sections, trusses and framed work, including cutting, hoisting, fixing in position and applying a priming coat of approved steel primer all complete.

Painting with synthetic enamel paint of approved brand and manufacture to give an even shade : Two or more coats on new work