Should You Pressure Wash Your Shingle Roof?

Should You Pressure Wash Your Shingle Roof?

Most homeowners well remember when they get their first house gadget. Chainsaw, riding mower, pressure washer — which one suddenly made you lord or lady of the manor? For many Massachusetts homeowners, that pressure washer suddenly makes everything a target, including your home's roof. Not so fast!

Long Legs

Unless you have long legs — and we mean freakishly long legs, like 15 feet or longer — you should not consider navigating your New Bedford-area home's roof.

A roof is slippery and dangerous, so the first reason to avoid pressure washing your shingle roof is safety. You cannot do the work safely, so don't do the work. 


The name of the tool, pressure washer, tells you a lot about the force it exerts on whatever your target is. A shingle is not designed to withstand that hard, focused stream of water.

You can do real damage to your home's roof by scouring the shingles with the pressure washer. At 1,000 to 1,900 pounds per square inch (PSI) of water pressure, the fun tool can tear off a shingle, force water up under your shingles, or saturate your sheathing.

Our second reason not to pressure wash your home's roof is practical. You could destroy it!


Why do you need to pressure wash the roof anyway? Are you trying to remove moss, algae, or streaks? You have a different problem with each issue, and a pressure washer is not a solution for any of them. 

For moss, most experts recommend physical removal by roofers equipped with safety gear and training; using the right tools, they can lift the moss from the roof, gently scrub away the roots, and leave the shingles clean and moss-free

For algae, (Gloeocapsa magma for you Latin fans), you want it off only for cosmetic reasons; it does no physical harm. Again, get a roofing crew to use a 50-50 bleach and water solution to spray wash the roof. Do not go on your roof yourself!

For streaks, have a roofer determine if they are simply algae or indicative of rust streaks from defective roofing nails or corroded flashing. Once more, use a reliable, local roofer to remedy the problem.  

In all cases, your best answer is not the pressure washer, but your helpful roofer. Couto Construction can provide practical solutions to all your roofing dilemmas. Contact us today to learn what we can do for you!