1) Scope
AC/GI/Aluminium sheets, tile roofing, shingles, including overlaps, ridges, hips.
2) Units
- m² (covering)
- m (ridges/hips/valleys)
- No. (roof accessories if specified)
3) Main Rules
- Laid area measured in plan including lapping as per spec; state sheet gauge/tile type.
- Ridges/hips/valleys measured separately in m.
- Fasteners included unless specified.
4) Deductions
- Openings >0.4 m² → deduct. Roof lights measured separately.
5) Special Notes
- Curved roofs: measure along slope with curvature noted.
- Insulation/vapour barrier separate items.
6) Example GI sheet roof plan area 320 m²; 4 skylights 1.2×1.2 m → 5.76 m² deduct; Pay = 314.24 m². Ridge 28 m separate.
