IBR is a square fluted profile with an effective covering width of 686mm designed for use as side cladding or roofing material in commercial, industrial and residential buildings. The name IBR is abbreviated from "Inverted Box Rib" and has became a household name in the South African Industry.

The deep broad flute design offers excellent drainage characteristics combined with optimum weight versus load/span capabilities.


IBR roof sheets are available in a wide range of materials displaying various structural properties. It should be noted that the load span characteristics are only to be used as a broad guideline as purlin spacing is also dependant on other factors such as the prevailing winds in a certain area, snow during winter periods, the presence of dust and other particles in industrial areas, the type of structure that is being erected etc.. We therefore recommend that an engineer is consulted to determine the purlin spacing for a specific application.


IBR sheeting is available in standard lengths up to 15 metres. The permissible length tolerance for the standard length range will be -+5 mm. Sheets outside these parameters are available on request and might be subject to special pricing arrangements. The maximum height which can be transported is 4.3 metres. This factor should be taken into account when bullnoses and curves are designed.


When using IBR, the recommended minimum pitch for roof slopes in excess of 30 m is 7.5º and for slopes less than 30 m is 5º. When IBR roof sheets are end lapped the roof pitch should be taken into account. The minimum end laps for roofs pitches in excess of 15º is 150 mm and for other roofs a minimum of 250 mm is recommended. End laps for side sheeting should be at least 100 mm. It is recommended that end and side laps on low pitch roofs are sealed to ensure watertightness.


The required number of IBR sheets can be calculated as follows:

Number of sheets = Length of building + gable end overhangs - 70 mm / 0.686 m (Cover width of sheet)

Roof sheets must be laid with one corrugation side lap with the narrow flute uppermost and shall be fixed through the crests of alternate flutes to purlins using 65 mm Top Speed or Tex screws into steel purlins and 90 mm Tex or Top Speed screws in the case of timber roofs, all fasteners shall incorporate 26 mm dia bonded washers.


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Overall Width: 740 mm

Effective Cover: 686 mm

Thickness: 0.3 - 0.8 mm

Length: up to 15 m

Material: Various
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