Image sourced from nzsteel.co.nz/products/zincalume
New Zealand Steel Limited introduced Zincalume®, zinc/aluminium alloy coated steel, to the New Zealand market in 1994. Zincalume® coated steel combines the barrier protections of aluminium with the sacrificial protection of zinc, giving the advantages of both metals. The resulting alloy coating enhances corrosion resistance, making it ideal for applications such as roofing and cladding.
Zincalume® coated steel represents a significant improvement on the traditional zinc coated galvanised steel. This is of particular value in New Zealand where the prevailing winds carry corrosive salt laden air many kilometres inland. Since its introduction, Zincalume® coated steel has been widely accepted and has the major share of the steel building products market.
Zincalume® has a finely spangled silvery matt finish. After exposure, the surface finishing darkens over time as the resin coating weathers away. This change is a natural one and visual only. The protective properties of the product are not affected.
Zincalume® is readily paintable using good quality primer and water-based acrylic topcoats. Paint manufacturers’ instructions should be followed. Dirt, grease and any loose material must be cleaned off the surface so the surface is clean and dry prior to the first coat being applied.
Handling and Storage
If your Zincalume® product becomes wet during storage, the product should be immediately seperated, wiped clean with a cloth and placed in a position where it can completely dry.
The fasteners durability should equal (or exceed) that of the roofing or cladding product and should be suitable for the environment. Stainless steel fasteners and lead headed nails should not be used
Zincalume® coated steel perofrms well in most areas not regularly washed by rainwater. However, regular washing of areas not naturally rain washed is essential to ensure longevity of the product and not voiding the product warranty.
In almost all applications, Zincalume® coated steel will out-perform galvanised steel. There are however, a small number of applications for which galvanised steel is more suitable.
Zincalume® coated steel must not be used for:
*Formwork in contact with wet concrete
*Products to be embedded in concrete. However, where very small volumes of concrete are involved (e.g. splashes) which are able to cure quickly, there is little corrosive effect
*Animal shelters where ammonia levels are constantly high
*Fertilizer storage sheds and containers
*Culverts, or where Zincalume® coated steel material is buried in the ground
*Highly alkaline environments (e.g. cement manufacture)
All stated above is a guide, and retrieved from NZ Steel. For more in-depth information, download NZ Steels brochure by clicking on the link below:
*Zincalume: Coated Steel