Are you getting what you specified?

You’ve chosen a profile (cladding system). You’ve selected a material grade and thickness plus a coating system. You’ve included all these details in your specification, so… the cladding is sorted… right? Not quite.

To an increasing number of entrepreneurs, this is merely an invitation to do business and let the buyer beware. Specifiers are particularly vulnerable when it comes to generic profiles (systems) or copyrighted brands that have or are in the process of becoming generic by misuse.

First off you need to understand the difference between a cladding profile and cladding system. The profile defines the geometric shape of the individual lengths of material whilst a system pertains to the profile together with the anchoring system plus all the ancillary items that combine to provide the waterproof envelope to a building.

The most common generic components are:

1) Cladding systems-corrugated (iron), IBR or box rib and concealed-fix.
2) Grade of material-CQ (commercial quality) and fullhard
3) Thickness – 0.4 0.45 0.47 0.50 0.53 0.55 0.58 0.60 and 0.80mm
4) Coatings – galvanized, Aluzinc
(Zincalume), colour-coated
(Chromadek), aluminium and stainless steel.

Theoretically we have a single corrugated cladding profile available in two widths 8,5/76 and 10,5/75. The 8,5 and 10,5 are the number of pitches between corrugations and the 76 is the pitch (distance) between the crests of individual corrugations measured in millimetres. The depth is fixed at 18mm (±1mm). In recent times numerous widths and/or depths
as low as 16mm have been foisted on an unsuspecting public. There is a noticeable difference in the spanning capabilities of 18 and 16mm deep corrugated cladding. IBR was a copyrighted name of a box-rib (trapezoidal) profile with specific geometry that was introduced in the 1960’s which has subsequently become the generic name for all box-rib profiles.

The original profile had a cover width of 686mm, five ribs spaced equally at 171,5mm, the ribs were 37mm deep, 35mm wide at the top and 69.5mm at the base.  Today there are profiles with much shallower and narrow ribs being passed off as IBR. Most reputable roofing profilers produce an IBR that complies with the original and market a variety of weaker profiles under various brand names.

It must be remembered that the spanning capabilities of a profile are directly proportional to the square of the depth of the ribs. There have been several generations of concealed-fix profiles ranging from narrow standing seams to trapezoidal ribs or a combination of the two. Klip-Lok although a copyrighted profile is trending toward becoming a generic name (with numerous corruptions of the spelling) for concealed–fix profiles with trapezoidal spring snap ribs.

201619 SteelConstruction V40E4 – SAMCRA