Structural Support

FRP roofing sheets must be adequately supported by a structural framework. The recommended purlin spacing varies based on the sheet profile and the anticipated load conditions:

• For standard industrial applications, purlin spacing of 1.2m to 1.5m is recommended
• For high-wind areas or roof configurations with minimal slope, closer purlin spacing may be required
• Structural steel or timber purlins should be used with appropriate corrosion protection

Thermal Expansion

FRP sheets expand and contract with temperature changes. This must be accommodated during installation:

• Use oversized holes for fasteners to allow movement
• Do not over-tighten bolts — secure firmly but allow movement
• Allow expansion joints at intervals for large roof areas

End Laps and Side Laps

Proper lapping is critical for weather-tight installation:

• End laps should be minimum 150mm for standard slopes
• Side laps should be minimum one complete corrugation
• Apply appropriate sealant in laps to prevent water ingress
• Maintain minimum roof slope of 5 degrees for efficient water runoff

Malaysia Climate Considerations

Tropical conditions in Malaysia require specific design considerations:

• UV-resistant gel coat is essential for long-term durability
• Consider wind load ratings for coastal and highland areas
• Adequate ventilation to minimize heat buildup underneath sheets
• Anti-condensation treatments available for humid environments

Fastening Guidelines

Use the correct fasteners and installation methods:

• Use only recommended fasteners with EPDM washers
• Fasteners should be placed at every corrugation at side laps
• Stramit or similar washers should be used to prevent galvanic corrosion
• Do not drill additional holes — use factory pre-punched holes where available