In short this is what is meant by the term galvanized it takes its name from the italian scientist luigi galvani.
Galvanized vs painted metal roofing.
Should i buy galvalume metal roofing or should i buy painted metal roofing.
It can also be painted and comes in many different looks.
The heavier the zinc coating the longer the protection.
Painted metal roof vs.
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.
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.
2 a new bare galvanized or galvalume roof will reflect more solar energy than most painted colors.
We get this question a lot.
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.
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.
Both types of steel can be painted to improve durability.
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.
Aluminum roofing comes with paint finishes as well and have their own warranties.
So what exactly is galvalume anyway.
Paint finish warranties are key to understanding the expected longevity of a galvanized or galvalume metal roof.
There are slight differences between stainless steel and galvanized steel.
For these reasons galvalume metal roofs are much more popular.
Lets dive in a little.
Technically yes however hot dipped galvanized steel resists corrosion in numerous environments for much longer than uncoated steel.
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.
Whether it is paint or galvanised steel any coating is designed to protect the base material.
Final thoughts on galvalume vs.
Galvanized steel metal roofing system properties.
The rust on galvanized will just continue to spread and get worse because it doesn t have that self healing property.
Galvanized steel is more durable than most other material utilized for building.
The answer to the question isn t always an easy one.
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 s the normal length of warranty on kynar 500 paint finish.