This code outlines the standard practices for laying and fixing semi-corrugated asbestos cement sheets for roofing and cladding. It specifies the requirements for purlin spacing, lap lengths, roof pitch, and the proper use of fasteners to ensure durability, weather-resistance, and structural integrity.
Laying of Asbestos Cement Sheets Code of practice, Part II: Semi-Corrugated Sheets
Quick Reference Values
minimum end lap150 mm
minimum roof pitch10 degrees (approx 1 in 5)
hole clearance2 mm to 3 mm larger than bolt diameter
standard j bolt diameter8 mm
Practical Notes
Never punch holes in asbestos sheets; always drill them to prevent cracking.
Holes must be drilled 2 to 3 mm larger than the bolt diameter to accommodate thermal expansion.
Always use bitumen washers backed by galvanized iron (GI) flat washers on fixing bolts to prevent water leakage.
Adequate safety precautions and masks must be used when cutting or drilling asbestos materials due to health hazards.