Galvalume Vs Painted Metal Roof
Stainless steel is generally a rust resistant material but it s corrosion resistance to salt depends on the stainless steel alloy or grade.
Galvalume vs painted metal roof. If you must go with steel make sure its galvalume or at the very least galvanized steel in case of steel shingles. 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. 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. Neither galvalume or galvanized substrate is warranted to be used in or around animal confinement or agriculture.
I can say from practical experience that nothing beats a white metal roof reflectivity 80 90 and high emissivity 80 90. At galvalume metal roofing. That s the normal length of warranty on kynar 500 paint finish. Aluminum roofing comes with paint finishes as well and have their own warranties.
That coating isn t as dense. All things being equal standing seam metal roof will cost more than metal shingles although performance wise they offer pretty much the same benefits and longevity. Paint finish warranties are key to understanding the expected longevity of a galvanized or galvalume metal roof. Bare galvanized and painted galvanized perform better in this type of environment.
Quick facts about galvalume. Stainless steel roofing system properties. Well first lets address a common misconception. Underneath a painted metal roof there is a galvalume coating.
With that being said the painted metal roof has a 40 year warranty on the paint and 30 year fade warranty. They have medium relfectivity and poor emissivity 15. Galvalume s formula was designed to combine the toughness and strength of zinc with the rust resistance of aluminum. Bare galvalume and painted galvalume sheets suffer rapid corrosion when in contact with mortar and concrete.
Also see a complete list of types properties of metal used in roof systems for more about galvalume. Painting a bare metal roof with white house paint dramatically improves preformance. Galvanized and galvalume metal roofs are hot roofs. There is not a substrate or paint warranty on galvalume products within 1 500 feet of saltwater corrosion resistance when compared to galvanized metal galvalume s corrosion resistance is about two to four times better.
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.