What is COLORBOND Steel
COLORBOND is the registered trademark for the prepainted steel product manufactured by BHP Flat Products Division. It consists of an oven baked paint system that is applied to ZINCALUME zinc/aluminium alloy coated steel. ZINCALUME steel combines the superior corrosion resistance of aluminium with the cut-edge protection of zinc. The coating system on COLORBOND steel includes a conversion coating, a corrosion inhibitive primer and a high performance exterior finish, that comes in a range of 16 attractive colours to blend with both the natural environment and other building products.
What About Corosion
COLORBOND steel carries a warranty of up to 25 years when used in typical residential environments. For more severe environments (for example, less than 200 metres from breaking surf), specific grades of COLORBOND steel are available to meet those special requirements.
What About Fading
Whether it be concrete tiles, clay tiles or COLORBOND steel, all roofing materials will fade eventually. Fortunately, COLORBOND steel will take longer to do so, and any fading will be uniform. Lighter colours will, of course, fade much less.
Care and Storage
Care and storage of COLORBOND steel prior to installation is vital to the life of the product when installed. If not required for immediate use, stack sheets or bundles neatly and clear of the ground, and provide cover as necessary to avoid the sheeting getting wet. A process called capillary action can cause corrosion which may lead to a reduced life expectancy or wet storage stain. Moisture on sheets or coil wraps of COLORBOND steel can penetrate between surfaces causing temporary softening of the paint film and the possibility of a minor colour change of some paint finishes. After drying, the coating will revert to its original state. Take extreme care with the surface until it has been dried and the coating hardness returns to normal.
Many COLORBOND steel products are supplied with a specially designed polyethylene strippable film called CORSTRIP. This film protects the sheet during storage and handling and should be stripped off immediately on installation. Sunlight can increase the adhesion so it is vital that sheets are not left uncovered outside. CORSTRIP film on coil should be removed within 12 months.
Bending and Roll-Forming
Bending and roll-forming of COLORBOND steel should preferably be carried out dry. If a lubricant is needed, it should be a fully volatile branched chain hydrocarbon type liquid.
Many COLORBOND steel products are supplied with a specially designed polyethylene strippable film called CORSTRIP. This film protects the sheet during storage and handling and should be stripped off immediately on installation. Sunlight can increase the adhesion so it is vital that sheets are not left uncovered outside. CORSTRIP film on coil should be removed within 12 months.uch as kerosene or distillate, should not be used on COLORBOND steel because they soften the paint film.
CORSTRIP polyethylene film provides excellent dry film lubrication.
The minimum bend radii recommended for COLORBOND steel should not be reduced as cracking of the paint film could occur. While these cracks are not always visible to the naked eye they may harbour dirt and, when used as external building components, result in tension bend corrosion.
Fasteners and Accessories
Selection of fasteners and accessories is crucial in ensuring the entire project enjoys maximum life. Fasteners used to fix roof sheeting must be chosen to last as long as the life of the COLORBOND steel. In all cases they should comply with Australian Standard 3566. Rainwater goods and roof flashings should always be made from a material which is at least as durable as the roof sheeting.
For example, avoid using COLORBOND XRW steel gutters with a COLORBOND XSE steel roof, or galvanized gutters with a COLORBOND steel roof. (BHP Coated Products Division no longer recommends galvanized steel for rainwater goods, roof flashings or cappings. Ask for ZINCALUME or COLORBOND steel by name). Following this advice will give you an installation which will avoid early failure of one or more components.
The phenomenon of an inert catchment has caused the demise of many a gutter. Roofing which does not change the quality or nature of rainwater as it flows across the roof is referred to as an inert catchment. This may be COLORBOND steel, terracotta tiles, sealed concrete tiles, acrylic sheeting, glass, ZINCALUME steel, or aluminium.
This means that virtually pure water plus any chlorides or acids dissolved in the rainwater from the atmosphere flows into the gutter. While galvanized steel gutters provided excellent service as catchments for old fashioned roofing materials such as unglazed tiles and galvanized steel, it is not serviceable as a catchment for modern, inert roofing products.