Surface-by-surface protection guide
Asphalt Shingle Roofing
Why high pressure ruins an asphalt shingle roof
High-pressure washing physically dislodges the protective granules bonded to asphalt shingles.
ARMA — the Asphalt Roofing Manufacturers Association, the trade body all major
shingle manufacturers follow — is explicit: “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.” Once granules are gone, the underlying asphalt is
exposed to UV and weathering it was never designed to face directly, and the shingle life
shortens permanently. There is no repair for lost granules — only replacement.
Granule loss from improper cleaning is also typically excluded from manufacturer coverage
— check the terms of your specific shingle warranty.
- Failure mode
- Granule loss from direct high-pressure impact → premature shingle failure, and damage typically excluded from manufacturer coverage.
- Our method
- Low-pressure bleach-based solution applied to the roof, 15–20 minute dwell time to break down algae and biofilm, then a gentle low-pressure rinse. No direct high-pressure contact with the shingle surface.
Tile Roofing
Why we never walk a tile roof
Concrete and clay tile are brittle under foot traffic and under direct pressure. A cracked
tile from a technician walking the roof, or from a pressure wand held too close, doesn’t
announce itself — it shows up later as a water stain on your ceiling, after water has
already found its way through the underlayment.
- Failure mode
- Cracked tile from foot traffic or direct pressure → hidden water intrusion under the tile.
- Our method
- Soft wash applied from ground-anchored or ladder-based positions without walking the tile field, low-pressure application and rinse matched to the glaze or coating on your specific tile.
Stucco & EIFS Elevations
Why pressure on stucco or EIFS causes hidden rot
Direct high pressure on stucco carves permanent lines into the finish coat — damage that
shows every time the light hits the wall at an angle. On EIFS (synthetic stucco), it’s
worse: pressure can puncture the thin base coat and force water behind the entire system, where
it has no way out. That trapped moisture causes hidden rot and mould inside the wall assembly
long before it’s visible from outside.
- Failure mode
- Carved surface lines on stucco; on EIFS, punctured base coat → water trapped behind the system → hidden rot and mould.
- Our method
- Soft wash under approximately 100 PSI, well below the threshold that stresses the finish or base coat, with detergent doing the cleaning work instead of pressure.
Travertine & Limestone Decking
Why acidic cleaners on travertine or limestone can’t be undone
Travertine and limestone are calcium carbonate — the same mineral acid dissolves. An
acidic cleaner used on pool decking or hardscape doesn’t just stain the stone, it etches
it: a permanently dulled, pitted surface. There is no sealer that reverses etching.
Once it happens, the only fix is professional honing and repolishing, or replacement.
- Failure mode
- Acidic cleaners dissolve calcium carbonate → irreversible etching, permanently dulled or pitted stone.
- Our method
- Pressure capped at 800–1,200 PSI, wide fan tip, minimum 12-inch standoff distance from the surface, pH-neutral cleaning solutions only — never acidic products on calcium-based stone.
Cedar Shake & Siding
Why pressure strips cedar’s soft spring wood
Cedar grows in alternating hard summer wood and soft spring wood. Pressure washing strips away
the soft spring wood first, leaving a permanently rough, “furred” surface that
can’t be smoothed back. Pressure can also force water under individual shakes or siding
boards, trapping moisture exactly where cedar is most vulnerable to rot.
- Failure mode
- Pressure strips soft spring wood → permanent furring and shortened material life; forced water under shakes → trapped moisture and rot.
- Our method
- Chemistry-led cleaning — the detergent does the work, not the water pressure. Rinse pressure never exceeds what a standard garden hose delivers.