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Dimond Topspan

Topspan is a high rib roofing profile that combines wide coverage with long span capabilities.  It has a curved rib top and a bold shape, allowing Topspan to achieve economy, style and ease of installation. Topspan is ideal for large commercial and industrial applications and the profile is also readily available in Dimond’s range of natural lighting systems.

Key Features
  • Cover: 900mm
  • Sheet Width: 970mm
Green Tag Certified
Green Tag Certified
Scope of Use
  • Minimum Pitch: 3 degrees (approx. 1:20)

Dimond long run metal roofing and cladding is intended for use in constructing the building envelope for commercial buildings and residential buildings subject to the limitations listed below.

Attention to the following details is required to ensure the expected system performance is achieved:

  • The selection of the type and grade of sheeting material and fasteners must be based on the life expectancy required and the severity of the external and internal environments.
  • Correct choice of breather type or vapour barrier underlay to suit the building environment.
  • Site storage that keeps product dry and protected from damage.
  • Sheeting handling that prevents surface damage.
  • Avoidance of excessive spans or insufficient fasteners for the expected loads.
  • Correct placement and flashing of penetrations through the roof.
  • Correct layout and installation of the sheeting, underlay and netting.
  • Allowance for thermal expansion and contraction.
  • Sufficient roof pitch to permit complete surface water drainage.
  • Control of allowable contact with dissimilar materials.
  • Awareness and implementation of maintenance requirements, particularly for surfaces not washed by natural rainfall.
  • Correct choice of material for collection of drinking water from a Zincalume or colour finished roof is required.
Limitations on Use
  • Not suitable for use as a platform for maintenance work.
  • If the need arises to use Dimond long run roofing & cladding outside the limitations and procedures given in the Performance Statements or other referenced literature, or if any doubt exists on product handling or use, written approval for use must be obtained from Dimond before the project commences.
3° Minimum Roof Pitch Required
Statement of Building Code Compliance

Test information available from Pacific Coilcoaters and BHP NZ Steel, and past history of use of long run metal roofing and cladding products in New Zealand indicate that, provided the product use and maintenance is in line with the guidelines contained in the current literature referenced, Dimond long run metal roofing & wall cladding systems can be expected to meet the performance criteria in clause B2 and E2 of the New Zealand Building Code, for a period of not less than 15 years.

In-Service History

Dimond is New Zealand's largest manufacturer of steel roofing, cladding, structural and rainwater goods.

For over forty years Dimond has been an industry leader in innovation, product development, technical backup and distribution excellence.

Other Performance Attributes

Green Tag:

  • All Dimond Roofing products roll-formed using ColorCote painted steel coil is Global GreenRate GreenTag certified and is applicable for Green Star and Home Star credits

Span Capacity

Roofing Span Capacity
Thickness  End span  Internal span
0.40mm 2.00m 3.00m
0.55mm 2.90m 4.30m

*To suit ultimate wind loads up to 1.5 kPa

Cladding Span Capacity
Thickness  End span  Internal span
0.40mm 2.40m 3.70m
0.55mm 3.30m 5.00m

*To suit ultimate wind loads up to 2.0 kPa

B2 Durability compliant
E2 External Moisture compliant
External Moisture
Dimond Roofing & Cladding Technical Manual
Span Tables
Environmental Information
Environmental Information
Specification Clause (Masterspec)
Installation and Operation
Dimond Homeowners Brochure
Colour Range
Additional Information

Dimond Roofing are a manufacturer of steel roofing, cladding and rainwater products.

Product Enquiries

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