Copper in ArchitectureFact 15 of 17
Shingles stained with unsightly algae have no copper in the roofing shingle granules to kill the roof algae. To remedy the problem, clean your roof with oxygen bleach and then install copper strips under roofing shingles to keep the black, streaky eyesore at bay. One strip, across the entire roof, having a two-inch exposure should protect 14 to 18 feet of the roof below it. To install, cut long 7- to 8-inch-wide strips of copper. Slide them up under the shingles until you hit the nails. Then, every four feet or so, lift a shingle tab and drive a copper nail through the copper strip. When you let the shingle tab back down, it should completely cover the nail.
