What does a metal roof coating actually do on a commercial building?
A metal roof coating forms one continuous rubbery skin over the panels, laps and fastener heads so water has no path into the building. On an older warehouse in the Ashland area, that skin covers surface rust, bridges the small gaps at panel side laps and wraps each screw washer.
The coating also changes how the roof handles sun. A light, reflective top coat bounces back much of the solar heat that a bare or faded steel panel soaks up. The Cool Roof Rating Council publishes rated reflectance values for roof coatings, which helps compare products.

