Keep That Power Washer Off Your Roof

As we head into spring and come face-to-face with a growing number of home clean-up projects, you may gaze up at your roof and have visions of power washers and chemical cleaners start dancing in your head. Our friends at Line Home Construction are here to tell you that you might want to think twice about that…

The Question: I have green moss that grows on my roof. My neighbors say leave it alone but I want to get it off. Should I use bleach, a power washer or something else?

The Answer from Line Home Construction: Moss tends to grow on houses that are surrounded by lots of trees but can also grow on areas of the house that don’t get lots of sunlight. Most houses have moss and mold grow on the north side of the roof. We recommend washing it off with regular water. No chemicals should be used when cleaning the mold/moss off. The use of chemicals will break down the natural resins of the materials, making them frailer and more susceptible to more moss/mold growing back.

Also we highly recommend you never—Never!—power wash your roof. Just like chemicals, it breaks the shingles down and makes them weaker. Power washing also has the effect of almost “sanding” the shingles, which is very bad. The easiest solution is to wash the moss/mold off with your hose. Another solution could be to get the new pressure-treated shingles that combat again moss and mold.

Have your own questions about roofing or other home-improvement issues? You can contact Line Home Construction at 631-287-5042. You may even see your question answered right here at Ask the Expert.