Dimond Topspan Roofing

Dimond Topspan Roofing & Cladding

Suitable for 3° and greater

900mm Cover width

970mm Sheet width

Topspan has a high rib

Suitable for light commercial

Suitable for commercial

5 ribs per sheet

Topspan is manufactured in Christchurch.

If this product is not suitable for your project... Click here to find product options suitable for your requirements.

Dimond Topspan Profile

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. These attributes allow 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.

Dimond Topspan Profile

Dimond Topspan Profile Dimensions



Sheet Width



3° (approx 1:20)

all dimensions given are nominal

Sheet Tolerances

Sheet width: ±5mm
Sheet width for aluminium +0, -15. If sheet cover widths are critical, advise Dimond at time of order.
Sheet length: +10mm, –0mm. For horizontal wall cladding where notified at time of order of intended use, tighter tolerances can be achieved +3mm, –0mm.

Profile Properties

Material options Steel 0.4mm* (1) Steel 0.55mm Steel 0.75mm* Aluminium 0.7mm* Aluminium 0.9mm Duraclad 1.7mm (total thickness)
Nominal weight / lineal metre (kg/m) 4.12 5.55 7.47 2.31 2.96 2.70
Drape curved roof - min. radius (m) n/r 120 120 n/r 120 30
Purlin spacings for drape curved roof (mm) (2) n/r 2400 2400 n/r 2400 1500
Machine crimp curved -roof min. radius (mm) n/a n/a n/a n/a n/a n/a
Unsupported overhang (3) 250 450 600 250 350 250

*Available only on request, subject to minimum order quantities. Check availability with Dimond.

(1) 0.4mm BMT not recommended for internal ceiling applications.

(2) Recommended maximum purlin spacing at minimum radius.

(3) Based on 1.1kN point load support, but not intended for roof access.

n/r – not recommended

n/a – not available

Roll-forming facility


Manufacturing location for Duraclad


Sheet lengths: Topspan is custom run to order. Where long sheets are used consideration must be given to:

  • special transportation licences for sheet lengths over 25m
  • site access for special lifting equipment
  • fixing techniques to accommodate thermal expansion
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