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Trapezoidal, or rib profiles, have sloping sided ribs and are fastened through the profile. They are available in a number of configurations to suit a wide range of performance and aesthetic criteria.

They can be categorised by common application into residential, commercial and industrial groups.

Steel & Tube roofing products offer four trapezoidal rib products with rib heights varying between 20mm and 30mm. These are typically utilised in domestic roofing, or commercial roofing and cladding applications where spanning ability is not a prime requirement. The five-ribbed product gives exceptional performance.

Key Features
  • Top coverage in its class for best economy
  • Can be crimp curved to 400mm radius
  • Minimum pitch 3°
  • Available in a wide selection of materials
  • Translucent sheeting available to match
Environmental Choice (ECNZ) Licensed
ECNZ Licensed
NZ-Owned Business
NZ-Owned Business
Scope of Use

Plumdek and Triform profiles feature a strong rib design coupled with wide economical cover, meaning they are equally at home in residential and commercial applications.

Appropriate for use as residential roofing and cladding, industrial/commercial roofing and cladding, and canopies.

Limitations on Use

In accordance with Acceptable Solution E2, the minimum pitch for Plumbdek for roofing dwellings is 3˚. Roof runs in excess of 40 metres should be checked for water runoff capacity.

3° Minimum Roof Pitch Required
NZS 3604 Corrosion Zone B suitable
Corrosion Exposure Zone B
NZS 3604 Corrosion Zone C suitable
Corrosion Exposure Zone C
NZS 3604 Corrosion Zone D suitable
Corrosion Exposure Zone D
NZS 3604 Wind Zone Extra High suitable
Extra High Wind Zone
NZS 3604 Wind Zone Specific Design suitable
Specific Design Wind Zone
Statement of Building Code Compliance

Clause E2 External Moisture: B1 Plumbdek will comply with the performance requirements of E2 when installed in accordance with E2/AS1. Alternatively, when designed in compliance with the NZ Metal Roof and Wall Cladding Code of Practice, or Steel & Tube Roofing Solutions Product Guide, Plumbdek will comply with Clause E2 where SLS wind loads do not exceed 3.0 kPa. 

Clause B1 Structure: In .40mm or .55mm steel, G550 grade (high strength) Plumbdek will meet the requirements of B1 for the following loads and spans. Figures are given for rib fastening with self drilling screws and proprietary load spreading washer to each rib. Pan fixing of wall cladding will also attain the same loads. For other materials or grades of material, or applications outside the attached graph, specific design is required.

Clause B2 Durability: With normal maintenance, the requirements of Acceptable Solution B2/AS1 will be met by nominated materials in the following environments as defined in New Zealand Steel Specifiers and Builders Guide June 2010.  

B1 Structure compliant
B2 Durability compliant
C Protection from Fire compliant
Protection from Fire
E2 External Moisture compliant
External Moisture
BIM Files Link
BIM-spec Full Library
Product Technical Statement
Colorsteel Resources
Environmental Choice NZ Award
Test Results
Maintenance Instructions
Specification Clause (Masterspec)
Colorsteel Material Selection
Brochure: Product Showcase
Brochure: Roofing Solutions Product Guide
Colour Range
Order Samples
Product Resources and Links

Steel & Tube are a New Zealand supplier of a range of steel products and services.

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