Roof Cleaning With a Pressure Washer | Is it Safe?

Many people are still confused about roof cleaning and whether or not it is safe to do on an asphalt shingle roof. The confusion comes from inexperienced bloggers and contractors trying to make money off of consumers. They are typically either selling inferior roof cleaning products or trying to drive traffic to a web page so they can sell ad space.

As a contractor, I do not benefit from telling you the truth. It may get me a few local jobs here and there but for someone reading this blog across the country, it does not benefit me at all. The truth about cleaning roofs is that it is safe and recommended by the shingle manufacturers but with guidelines. You can look it up yourself by doing a search online. They recommend the use of a bleach mix applied with low pressure to clean shingles suffering from roof algae. They produce the shingles, they know the material better than anyone else, so wouldn't it make sense to follow their recommendations? I think so.

Yet there are people out there that call themselves contractors writing articles and doing videos on roof cleaning and suggesting that it is safe to use a pressure washer. The shingle manufacturers like Owens Corning and GAF warn against the use of a pressure washer! Why anyone would go against what the shingle producers warn against is beyond me. Like I said before, they are just trying to increase traffic to their web pages so they can sell products or ad space and make money. A certain "ask the builder" blogger, among others are simply giving false information to consumers.

Would you do something harsh to your vehicle if a certified mechanic warned you against doing it? I don't think so but the problem is that consumers come across these bad information sites before they find a truthful one and then it is too late. The bottom line is never wash your asphalt shingle roof or allow anyone else to with a high pressure washer. The excessive pressure may not result in immediate visual damage but it will lessen the longevity of your roof. There is a much better way to rid a roof of mold, lichen, and algae and it is the way the shingle manufacturers recommend; low pressure.