BILL NR. 03: MAIN HOUSE ELEMENT NR. 07: ROOF PATENT CORRUGATED ROOF SHEETING SYSTEM Decra type "Shingle" 4 mm. thick x 370 x 1320 mm. zincalume interlocking sheet tile coated with natural stone finish as supplied by Nabaki Afrika Limited fixed in accordance with the Manufacturer's instructions Coverings fixing to and inclding 50 x 50 mm treated softwood batens at 300 mm centres ; sloping not exceeding 45 degrees from horizontal and fixed with Decra galvanized nails Decra zincalume sheet accessories and fittings fixing with Decra galvanized nails Decra trapezoidal ridge and hip cap 149 mm. girth Decra box barge cover cap 230 mm. girth INSULATION QUILTS AND FOILS Decra "Decrafoil" aluminium foil insulation quilt as supplied by Nabaki Afrika Limited fixed taut over structural timbers with 200 mm side and end laps Coverings fixing to treated softwood battens at 500 mm centres ; sloping not exceeding 45 degrees from horizontal fixed with Decra galvanized nails ROOF STRUCTURE CARPENTRY STRUCTURAL TIMBER Pitch pine structural grade 1 ; treated 50 x 150 mm Wall plates ; spiked to masonry 50 x 150 mm rafter and bearers in trusses 50 x 150 mm ties and beams in trusses 50 x 50 mm. purlins