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  • Writer's pictureTomas Rojo Angeles

Why pressure washing your roof is NOT recommended.

showing an image of moss on a roof next to an image of the same roof that has been cleaned professionally in Seattle WA
Before and After Professional Roof Cleaning in Seattle

It’s okay to pressure wash cement, metal, or tile roofs, but if a roof cleaner you hired is pressure washing your cedar or asphalt shingle roof, they’re an amateur and you need to hire someone else. Pressure washing a cedar or asphalt shingle roof is not recommended because the high pressure water damages the shingles. Metal roofs, cement roofs, and roofing materials made from clay tiles or slate tiles are fine to pressure wash, because these materials aren’t damaged by pressure washers, although it’s still recommended to use a lower pressure for these types of roofs. Asphalt shingles and cedar shingles, however, should never be pressure washed no matter how low the pressure is, because they’re softer materials which are more prone to damage. The fragile cedar shingles can lose their protective coats and staining, or be disturbed and displaced by the water pressure. The same goes for asphalt shingles which are damaged by the high pressure water, and can be displaced causing water leaks, mildew, and mold in your attic.

For these more fragile types of roofing materials that shouldn’t be pressure washed, a soft wash by hand is recommended for cleaning. Even scrubbing the shingles by hand should be done by an expert to avoid damage. Professional roof cleaners will know the proper method for cleaning your type of roof, and they work carefully to ensure no damage is caused by their brushes and washing methods.

The team at Rojo Moss Removal & Power Washing, LLC hopes this information answered your question. If you have more questions, or wish to order roof cleaning in Seattle, get in touch with our experts today and get a FREE quote by calling - (206) 228-7591.


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