providing corrugated g.s. sheet roofing including vertical / curved surface fixed with polymer coated j or l hooks, bolts and nuts 8 mm diameter with bitumen and g.i. limpet washers or with g.i. limpet washers filled with white lead, including a coat of approved steel primer and two coats of approved paint on overlapping of sheets complete (up to any pitch in horizontal/ vertical or curved surfaces), excluding the cost of purlins, rafters and trusses and including cutting to size and shape where