Reflected sunlight from a defective window burned this composite decking.
Dave McIntosh/McIntosh Builders Reflected sunlight from a defective window burned this composite decking.

A customer recently sent me pictures of one of his deck installations showing a black arc about 5 feet long and 3 inches wide that had been burned into the surface of composite decking (see photo, left). The arc follows the path of sunlight reflected from a second-story window. Because the builder thought that the hot spot that burned the decking was caused by distorted glass in the window rather than by a product defect in the decking, we didn't approach the decking manufacturer about the problem. We simply replaced the affected planks, and the builder provided the labor to install it. The window manufacturer replaced the glass, which seems to have eliminated the hot spot. Thankfully, the builder’s client didn't try to get a tan in that same location, though I suppose that one would have to lay there a long time to get burned like that.

John Duddleston
Mead Clark Lumber Co.
Santa Rosa, Calif.