Galvanized Vs Painted Metal Roof
Also see complete list of types properties of metals used in roof systemsfor more about galvanized steel roofing.
Galvanized vs painted metal roof. Whether it is paint or galvanised steel any coating is designed to protect the base material. Paint finish warranties are key to understanding the expected longevity of a galvanized or galvalume metal roof. The standard is a 55 a z coating underneath the painted metal is a 50 a z coating. Aluminum roofing comes with paint finishes as well and have their own warranties.
But galvalume has an excellent performance life in bare exposures as well. The problem with galvanized metal painted or not is that once it starts to red rust it doesn t eventually stop as galvalume does. That coating isn t as dense. As far as the warranty goes metal roofs hold up great and.
Most galvalume like galvanized steel is coated. Apply the sherwin williams paint and primer to a galvanized roof with a paintbrush or a roller specifically designed for corrugated metal. Additionally primer and paint adhere better to galvalume coated panels and they carry a 20 year limited warranty while galvanized panels do not making them a smarter long term investment for your customers homes agricultural buildings or commercial properties. That s the normal length of warranty on kynar 500 paint finish.
Underneath a painted metal roof there is a galvalume coating. Paint adheres better to galvanized steel than to galvalume so it requires repainting less often. If crawling around on a metal roof in the hot sun does. Technically yes however hot dipped galvanized steel resists corrosion in numerous environments for much longer than uncoated steel.
The coating corrodes instead of the core material. Galvalume metal roofing system properties. Details about galvanized metal roofing are at galvanized steel roofs. Final thoughts on galvalume vs.
With kynar 500 or hylar 5000 paint finish or its equivalent you will not have to paint over your steel roof for at least 30 years. The metal roofing alliance recommends g 90 galvanized steel for roofing which has 90 ounces of zinc per square foot. Both types of steel can be painted to improve durability. Both galvanized steel and galvalume weigh 100 to 150 pounds per 100 square feet and contain about 35 recycled materials.
The big difference is that aluminum will oxidize chalk if exposed to the elements but the aluminum will not look unsightly and continue on with a rapid oxidation process deterioration rust as steel will.