Steel & Tube's high strength galvanised cold formed steel purlins (HST) with accessories, provide a total system suitable to support a wide range of roofing and cladding materials.
In addition the HST purlin sections can be readily adapted to a wide range of other applications such as floor joists, ceiling support members and load bearing wall studs.
Performance:
HST purlin and girt loads are presented in limit state format in full compliance with NZS 4203:1992 "Code of Practice for General Structural Design and Design Loadings for Buildings".
Load capacities have been determined in accordance with AISI "LRFD Cold-Formed Steel Design Manual" 1991 and confirmed by a comprehensive full scale testing programme.
Load tables are available in ultimate strength load format on request from your local Steel & Tube Distribution branch.
Durability:
Provided HST purlins, girts and accessories are not exposed to moisture, service life can be expected to exceed 50 years, complying with the durability requirements of NZBC Approved Document B2.
For applications affected by salt water or other corrosive conditions specialist advice should be sought.
Length:
For ease of transportation and handling on site, the bundling length should be limited to 18 metres. Lengths exceeding 18 metres are subject to transport and handling facilities by arrangement. Your local Steel & Tube Distribution branch can assist you with such arrangements.
Materials/Finish:
Purlin braces and accessories are formed from hot dipped galvanised steel grade 250. HST purlins and girts are rolled from hot dipped galvanised high strength steel strip grade 450/500. The base metal thickness, Grade and Zinc Weight is outlined as follows:
1.15–1.45 mm 500 (MPa) 275gm/m2
1.75–2.0 mm 450 (MPa) 275gm/m2