The technology of pressed steel roofing
A Gerard roof is made up of individual lightweight steel panels, pre-pressed and coated with multiple protective layers. The panels are secured using a unique horizontal fixing system that effectively locks them together to form a single structural unit with greater holding power and protection than most other roofing systems. The resulting roof is stylish, copes with severe weather and lasts a very long time.
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Gerard pressed steel roofing begins with the strength and resilience of New Zealand steel, coated on both sides with a protective layer of aluminium-zinc. This resilient alloy combines the sacrificial protection of zinc, as used in galvanising, with the natural barrier protection of aluminium. In almost every environment, Gerard pressed steel roofing provides superior performance and a significantly longer service life than galvanised steel roofs.
Gerard pressed steel panels are primed and pressed to shape before the final protection layers are applied. This avoids the problem of micro-cracking, which can occur in the bends of products pressed from pre-painted steel like longrun.
Finishing top coats are baked on to ensure a consistently even coating. For our satin finish tiles, a 45-micron topcoat of ultra-tough polymer acrylic is applied. This is more than twice the thickness of the paint on typical pre-painted coloured steel products. Our textured tiles are finished with a polymer bonding basecoat, granulated natural stone or ceramic coated stone and a clear acrylic overglaze. The result is a powerful combination of up to nine protective layers.
Most roofing systems are attached using vertical fastenings. Their weakest holding direction is parallel to the vertical lifting forces created when high winds pass over a roof, like air over an aircraft wing. Gerard pressed steel panels, however, are designed for horizontal fastening. This is the strongest holding direction, because it is at right angles to the lifting forces. Plus there are eight to ten fasteners holding down each Gerard panel. Where whole neighbourhoods have lost their roofs in storms, Gerard roofs have held fast and continued to protect their owners’ homes.
A large scale fire can quickly spread from house to house, as flying embers find their way into the roof space of one house after another. Gerard pressed steel roofs have proven their fire resistant qualities in many fierce blazes. They exceed the world’s most stringent fire test standards and are securely interlocked to significantly reduce the chance of flying embers entering the roof space.
With its combination of light weight and superior strength a Gerard pressed steel roof can place significantly less stress on structures weakened by earthquake or fire. For example, a 10 tonne concrete or clay tile roof area could weigh as little as one tonne with Gerard satin finish panels, or 1.7 tonne with Gerard textured panels. Either way, it’s a very reassuring difference when the earth starts to move.