Roof Wind Load Table

The table below recommends weight series and fixing frequency for Alsynite Glass Reinforced Polyester sheeting to accomodate a nominated internal purlin spacing at a wind load of up to 1 Kpa. For wind loads in excess of 1 Kpa refer to the Alsynite Technical Department for sheet weight and spanning recommendations. Note: For end spans, reduce the span figure by 20%


Series (GSM) 2400 3050 3660 4270 4880 Recommended amount of main fasteners
  Roof, Crest fix Wall, Pan fix
Mid span End span Mid span End span
Trimdek (Mono clad) 1500mm 1700mm 2000mm 2200mm 2600mm 5 5 4 4
Custom Orb (Corro) 1200mm 1500mm 1700mm 1750mm 1800mm 4 6 6 6
Spandek 700 1600mm 2000mm 2300mm 2600mm 2800mm 5 5 5 5
Kliplok 406 & 700 1400mm 1700mm 2000mm 2300mm 2700mm 3,4 3,4 3,4 3,4
LT7 1700mm 2100mm 2400mm 2600mm 2800mm 6 6 6 6
Speedek 500/700 1400mm 1700mm 2000mm 2300mm 2700mm 3,4 3,4 3,4 3,4


  • Fixing Specifications should be in accordance with AS/NZS 1562.3:1996 Plastics Building Sheets - General Installation Requirements and Design of Roofing System.
  • The sheet weights recommended are designed to withstand the effects of column expansion caused by thermal movement of the entire roof structure and to provide a sheet of the weight and strength necessary to complement the metal roofing specified and the supporting structure.
  • The drilling of oversize fastener holes is required to allow for thermal expansion and contraction
  • For sheets up to 10m - drill clearance hole of 10mm dia.
  • For sheets above 10m - drill clearance hole of 15mm dia.
  • For roof installations, fasteners must be fixed to the ribs. For wall installation; rib fixing is recommended, however valley fixing can be used in low wind load areas.


Note: Single sheet lengths above 16m are not recommended with the exception of the Free span 700 profile