Yes, a roof can be pressure washed without damaging the shingles by using a PSI lower than 1500, a 40-degree nozzle, and a pressure washer detergent. Cleaning the roof with a pressure washer should start at the highest point and end near the access point, in order to avoid slipping on wet tiles. The pressure of the unit should be tested on a small area and adjusted on the way. The safe way to pressure wash a roof is to divide the area into small sections and power clean them one at a time. Pointing the nozzle under the tiles and stepping on shingles that have mold, moss, or algae should be avoided.
How to pressure wash a roof is discussed in detail below.
Is It Safe to Pressure Wash a Roof?
Yes, it is safe to pressure wash a roof if the pressure applied is low and if the right equipment is used. Asphalt and other types of shingles have protective coatings that prevent weather elements from damaging them, although they are still thin. Using a pressure washer at the lowest setting and from a safe distance can get the dirt out of the roof without damaging the protective coat. The pressure washer should be set on a flat surface when pressure washing a roof because it can have a kickback when started, which can put the user at risk, unless it is a portable pressure washer that doesn’t have a kickback.
Is There Still a Way Around It?
A roof can be washed by applying the method named soft washing that involves using a pressure washer at a low-pressure setting and the right nozzle, preferably black or white, that can spread out the pressure. Stepping on the wet shingles and algae is not recommended and pressure washing a roof should be done on a sunny day.
How to Pressure Wash a Roof
To pressure wash a roof, follow the steps explained below:
1. Cover the Sensitive Areas
Plants and other sensitive areas should be covered with a tarp before pressure washing a roof to prevent detergents from pouring down on them.
2. Attach the Correct Tip
The power coming from a portable pressure washer should be controlled by using the right spray tip. A 40-degree or wider nozzle is suitable for pressure washing a roof since it won’t damage the shingles.
3. Spray the Solution
To pressure wash a roof, turn the pressure washer at the lowest setting, point it downward, and spray the roof with the Brigs & Stratton detergent or other soap that can kill algae and remove dirt from the shingles.
4. Wash It Off
The detergent should be applied at the top of the roof several shingles at a time so it pours down the roof. Spraying water or detergent upwards of the roof can move or damage the shingles. The same pair of shingles shouldn’t be pressure washed for too long, otherwise, doing so can damage them.
5. Inspect the Roof
The roof should be inspected each time after it is pressure washed to check if there are any leaks or damaged shingles that should be taken care of.
