Yes, if the wrong method is used — full-force pressure washing strips the protective granules off asphalt shingles and can drive water under tiles, cutting years off a roof's life. Soft washing (low pressure plus a cleaning solution) removes the same algae and moss safely, which is the only method Cleveland Pressure Washing, rated 4.9 from 28 reviews, uses on roofs.
What actually causes the damage?
A pressure washer aimed directly at asphalt shingles knocks loose the granules embedded in the surface — those granules block UV rays and shed water, so losing them ages a roof faster and can void a shingle manufacturer's warranty outright.
- Granule loss thins the shingle's protective layer and shows up as bald or faded patches
- The same force can lift shingle edges or force water up underneath them, which surfaces later as a leak with no obvious cause
So how do you clean a roof safely?
Soft washing skips the mechanical force entirely. A diluted cleaning solution is applied at low pressure, left to break down the algae and moss at the surface, then rinsed away — no scrubbing, no blasting, no granule loss. It takes longer than a straight pressure wash would, and that extra time is the tradeoff for not shortening the roof's life.
What if I've already had a bad experience with a pressure washer on a roof?
That's a common reason people search this question, and it's a fair concern — a roof washed with the wrong method once can show bald patches or thinning granules that don't reverse. It's also why Cleveland Pressure Washing treats roof work as a soft-wash job by default rather than an option to upsell into; getting that call wrong is expensive for a homeowner and a bad look for the business.
Is soft washing enough to remove black streaks on my roof?
Yes — those streaks are algae growth, and a soft-wash cleaning solution breaks it down at the root rather than just knocking it off the surface, which is why it grows back slower than after a plain rinse.
Will pressure washing void my roof warranty?
It can — most shingle manufacturers exclude granule loss from high-pressure cleaning, and stripping granules is exactly what a direct pressure blast does. Soft washing doesn't carry that same risk, which is why it's the standard approach for roofs.
Can gutters get damaged during a roof wash?
They can if water and debris get pushed into them carelessly during the rinse, so gutters typically get flushed as part of the same visit rather than left to catch runoff on their own. Ask whether gutter clearing is included before booking.
How do I book a roof wash?
Call (216) 999-4953 — Cleveland Pressure Washing is open seven days a week, 9 AM to 8 PM, and can talk through the roof's condition before scheduling a soft-wash visit.