Join the MRA | Member Login
Find a Professional
Sign Up Log In Add New Topic

TOPIC: Standing Seam roof

White Streaks, Oxidation?

Return to Standing Seam roof

Return to Archive

Return to Forum

Our standing seam galvanized roof is showing some white streaking in areas. I presume this is oxidation, just like on an old galvanized bucket. Is this normal, is it detrimental? Can I clean or coat the roof to avoid this? Many thanks.
Guest User

5/14/2002
I have a 20+year old white metal roof on my garage.The area around the building is surrounded by large pines. The roof has aquired a coating of grit an dirt from the trees. We live in an area of heavy snow, but now the snow no longer slides. We intend on power spraying the roof. Is there a product out, that we can coat the roof with? What can we do to restore the slipperyness to this roof? Thank You, Gail
Guest User

9/14/2002
Chances are that just cleaning it will help a lot by making it slicker. The snow slides also partly because the reflectivity of the metal helps to cause the snow to melt from underneath. Having the roof be cleaner could help with this as well. Also, you could repaint the roof if you wish, using a quality paint suggested for this purpose by a quality paint store. Though I have never worked with them before, thee are also some coatings available similar to what you're seeking. One example can be seen at: http://www.everbrite.net/index.htm Good luck! Todd Miller
Todd Miller
Isaiah Industries, Inc.

9/14/2002
Sorry for the delay, but we just found that your question had not been answered and hope we are not too late. Yes you are right that it is probably oxidation however the roof should not be streaking and it is an indication that the sheets became wet in the pile prior to instalation. This will probably be the first point of failure of the galvaizing at some point in time. You can try cleaning it with a little TSP and a scub and depending on how advanced it is. You want to make sure that it does not get to the metal core at the red rust stage. You can paint the areas with a zinc rich paint which will restore the sacrificial protection of the zinc surface however it may make your roof blotchy and you may want to have the whole roof coated.
Allan Reid
Dura-Loc Roofing Systems, Inc.

9/17/2002