Dimond Brownbuilt 900 High rib roofing profile

Dimond Brownbuilt 900 (BB900) Roofing and Cladding

Suitable for 3° and greater

900mm Cover width

960mm Sheet width

Brownbuilt 900 (BB900) has a high rib

Suitable for residential

Suitable for light commercial

Suitable for commercial

7 ribs per sheet

Brownbuilt 900 (BB900) is manufactured in Auckland.

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

    • Suitable for 3° and greater

      900mm Cover width

      960mm Sheet width

      Brownbuilt 900 (BB900) has a high rib

      Suitable for residential

      Suitable for light commercial

      Suitable for commercial

      7 ribs per sheet

      Brownbuilt 900 (BB900) is manufactured in Auckland.

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

Dimond Brownbuit 900 Profile

Brownbuilt 900’s strong angular ribs resist bucking, offers good resistance to foot traffic whilst maintaining an eye-catching aesthetic. Primarily used in large scale commercial buildings, BB900 also creates a striking look on a home.

When inverted BB900 Reverse Run can be used as wall cladding; enhancing the design of your project.

Fastener Design

Brownbuilt 900 should be screw fxed to either timber or steel purlins. The use of the appropriate length of 12g or 14g screw will ensure failure by screw pull out will not occur under loads within the scope of the Limit State Load / Span Capacity Chart.

Purlin Type Roofing Rib: Screw Length* (mm) Roofing Rib: Designation Wall Cladding Pan: Screw Length* (mm) Wall Cladding Pan: Designation
Timber 75 T17 - 14 - 10 x 75 50 Roofzip M6 x 50 HG-Z4
Steel 65 Tek - 14 - 10 x 65 or Tek - 12 - 14 x 68 20 Tek - 12 - 14 x 20

* If sarking or insulation is used over the purlins or for wall cladding fixed onto a cavity batten, into the stud, the screw length will need to be increased.


For screw size range and fastener / washer assembly refer Section 2.2.3.1. of the Dimond Roofing and Cladding Technical Manual.

The Limit State Load / Span Capacity Chart is based on 6 screw fasteners/sheet/purlin without the use of load spreading washers (except for Duraclad material, which must be fitted with either profiled metal washers and 36mm EPDM seals, or 32mm Weatherlok washers).

Profiled metal washers are recommended for use:

  1. On end spans, or large internal spans where the Ultimate Limit State distributed load is limiting. Contact Dimond for specific advice in these design cases.
  2. When required to enable the fixing system to accommodate the thermal movement of long sheets.
  3. Wherever the designer wishes to ensure the risk of fastener over-tightening will not cause dishing of the crest of the profile rib.

Use in serviceability categories (1) or (2) can allow the reduction of fasteners to 3 screw fasteners/sheet/purlin by using 3 fasteners/sheet/purlin. If this is done, the distributed load capacities given in the chart should be reduced using a multiplying factor of 0.5.

Long spans may require the specification and use of side lap stitching screws.

Design Example

Restricted access roof, 0.55mm G550 steel Brownbuilt 900 has a maximum end span of 2400mm and a maximum internal span of 3400mm. The following distributed load capacities apply.

BB900 6 fasteners / sheet 3 fasteners / sheet
End Span 2300mm 2300mm
Internal Span 3400mm 3400mm
Serviceability 2.0 kPa 1.0 kPa
Ultimate 4.0 kPa 2.0 kPa



Brownbuilt 900 Fastener Layout Options

Brownbuilt 900 3 Fastener/sheet Layout Brownbuilt 900 6 Fastener/sheet Layout
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