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Roofing & Walling Solutions – Technical Details

Roofing and walling offer significant benefits for any building. Queensland Sheet Metal offers a range of roofing and walling solutions for your needs. We have a large range of colours and profile choices from which to select. Ask us about your design options and colour choices for your building project.

We’ve also put together some technical information to help you with cladding and walling installation.

Wind Capacity for Cladding Purposes

Wind Capacity Tables are based on Australian Standards 1562.1-1992 and AS4040.0, 1 and 2-1992. Span tables are based on Australian Standard 4055-2006 “Wind Loads for Housing” and AS/NZS 1170.2:2002 for related applications.

Calculations for spans

Calculations for spans are based on wind speeds for non-cyclonic areas. For domestic building applications, these calculations are based on a maximum: eaves height of six metres, roof pitch of 35 degrees and total roof height of 8.5 metres. For commercial premises, tables are based on a maximum overall height of ten metres.
• Roofing calculations are based on Cpe=-0.9 and Cpi=0.2,
• Walling is based on Cpe=-0.65 and Cpi=0.2.
• A local pressure factor, Kl=2.0 has been used for roofing and walling spans.
• All pressures have been calculated on the basis that wind loading in any direction is not affected by local factors like terrain or shielding.
• The following shielding factors have been to calculate shielding according to standard categories: Category 3 = 0.85, Category 2.5 = 0.95, and Category 2 = 1.
• The carport and veranda spans apply to structures not bounded by exterior walls. Spans are based on Cpn=-0.9 and Kl=1.5. Loads may be determined over the entire span, and may be used for all span types.


Wind loading calculation

It is recommended to use the proscribed local wind classification for the building location. In the case of commercial and industrial applications, choose the location and wind category for that location, then convert to the wind classification using our table below.

Wind Load Conversion
Wind Classification (Domestic) Region & Category (Commercial / Industrial)
N1 (W28) Region A, Category 3
N2 (W33) Region A, Category 2.5 – Region B, Category 3
N3 (W41) Region A, Category 2 – Region B, Category 2.5
N4 (W50) Region B, Category 2