Can You Pressure Wash Asphalt Shingles?

No. Not "be careful," not "only on a low setting" — the asphalt roofing industry's position is that a pressure washer should never touch an asphalt shingle roof.

What the manufacturers' association says

The Asphalt Roofing Manufacturers Association (ARMA) puts it in plain language in its cleaning guidance: never use a pressure washer to clean an asphalt shingle roof, as this will cause granule loss and very likely premature failure of the roof system. A separate ARMA bulletin adds: do not use a power washer, or any brush or broom, on the roof surface.

Why it does damage

The colored granules on a shingle aren't decoration. They shield the asphalt underneath from UV and weather. High-pressure water knocks those granules loose — you'll see them collect at the bottom of downspouts after a pressure washing. Once bare spots form, the asphalt degrades faster, and you've traded a cosmetic algae stain for actual shingle wear. That's the "premature failure" ARMA is warning about.

What to do instead

ARMA's recommended method:

1. Apply a cleaning solution (sodium hypochlorite and water) with a sprayer
2. Let it dwell 15–20 minutes — don't let it dry
3. Rinse with low-pressure water

That's soft washing. It's the whole basis of our roof cleaning in Baton Rouge, and there's a step-by-step in how professional roof soft washing works.

"But my neighbor's guy pressure washed theirs and it looked fine"

It looked fine that afternoon. Granule loss doesn't show up as a dramatic before/after — it shows up as a roof that needs replacing a few years earlier than it should have. If a contractor offers to pressure wash your roof, that tells you what you need to know about the contractor.

If your roof is already worn enough that cleaning feels beside the point, that's a different question — see roof cleaning vs roof replacement.

---

Get it cleaned the way the manufacturers recommend. Request a quote.