Video: A Warning About Roof Cleaning

You should never use a power washer to clean roofs. in the United States, the most common roof is asphalt shingles. Asphalt shingles have granules which protect the shingle itself. Roofing manufacturers, including the asphalt Roofing Manufacturers Association, make it very clear that you should never use pressure to clean asphalt shingles. The second most common roof in the United States is concrete tile. If you use a pressure washer, using pressure to clean the concrete tile, you're trying to remove the bacteria buildup, which is typically dark and typically found on the north face. But when you use pressure, You're removing what is visible of this biological growth, but you're also removing the outer layer of the tile, which contain all the colors, all the oxides. So you should never use a pressure washer to clean concrete tile Or asphalt shingle, the damage that's done is irreversible.