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.

I can say from practical experience that nothing beats a white metal roof reflectivity 80 90 and high emissivity 80 90. With that being said the painted metal roof has a 40 year warranty on the paint and 30 year fade warranty. Details about galvalume are. Bare galvanized and painted galvanized perform better in this type of environment.

Underneath a painted metal roof there is a galvalume coating. 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. At galvalume metal roofing. That coating isn t as dense.

Bare galvalume and painted galvalume sheets suffer rapid corrosion when in contact with mortar and concrete. 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. Aluminum roofing comes with paint finishes as well and have their own warranties. Stainless steel roofing system properties.

Paint adheres better to galvanized steel than to galvalume so it requires repainting less often. 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. Galvanized and galvalume metal roofs are hot roofs. Paint finish warranties are key to understanding the expected longevity of a galvanized or galvalume metal roof.

They have medium relfectivity and poor emissivity 15. That s the normal length of warranty on kynar 500 paint finish. Painting a bare metal roof with white house paint dramatically improves preformance. Galvalume s formula was designed to combine the toughness and strength of zinc with the rust resistance of aluminum.

Well first lets address a common misconception. The standard is a 55 a z coating underneath the painted metal is a 50 a z coating. If you must go with steel make sure its galvalume or at the very least galvanized steel in case of steel shingles. Quick facts about galvalume.

Also see a complete list of types properties of metal used in roof systems for more about galvalume.