Galvanized Vs Painted Metal Roofing

Final thoughts on galvalume vs.

Galvanized vs painted metal roofing. So what exactly is galvalume anyway. The problem with galvanized metal painted or not is that once it starts to red rust it doesn t eventually stop as galvalume does. Paint does not adhere as well to galvalume so the aesthetics may not be as good. To protect against corrosion the steel is bonded to a layer of zinc which works as a sacrificial coating on the surface and also offers some protection to cut edges and nicks by flowing to these areas.

Paint finish warranties are key to understanding the expected longevity of a galvanized or galvalume metal roof. Lets dive in a little. Should i buy galvalume metal roofing or should i buy painted metal roofing. Technically yes however hot dipped galvanized steel resists corrosion in numerous environments for much longer than uncoated steel.

There are slight differences between stainless steel and galvanized steel. For these reasons galvalume metal roofs are much more popular. Galvanized steel metal roofing system properties. 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.

Also galvalume costs more than galvanized metal roofing but the fact that a galvalume metal roof will last up to twice as long as a galvanized roof of the same thickness could make up the difference. The rust on galvanized will just continue to spread and get worse because it doesn t have that self healing property. Galvalume is a sheet steel product covered with an aluminum zinc. The answer to the question isn t always an easy one.

2 a new bare galvanized or galvalume roof will reflect more solar energy than most painted colors. That s the normal length of warranty on kynar 500 paint finish. Whether it is paint or galvanised steel any coating is designed to protect the base material. 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. Aluminum roofing comes with paint finishes as well and have their own warranties. However over time the reflectance of galvalume drops some but the reflectance of galvanized drops significantly painted roofs have less change in relectance over time. The coating corrodes instead of the core material.

Paint adheres better to galvanized steel than to galvalume so it requires repainting less often. We get this question a lot. It can also be painted and comes in many different looks. The heavier the zinc coating the longer the protection.

In short this is what is meant by the term galvanized it takes its name from the italian scientist luigi galvani.