Roof Cleaning

No — high-pressure washing strips the protective granules off asphalt shingles, drives water under them, and can void your shingle warranty. That's why Wet Jet uses soft washing on roofs: low-pressure rinse plus a roof-safe cleaning solution that kills algae, moss, and lichen at the root without damaging the shingle surface.

Those black streaks are Gloeocapsa magma — a hardy blue-green algae that feeds on the limestone filler in asphalt shingles. It spreads fastest on the shaded, north-facing slopes of Northeast Ohio roofs because our humid summers keep shingles damp longer. Left alone it shortens shingle life and raises cooling costs by absorbing more heat. Soft washing kills it at the root.

Pressure washing uses 1,500–3,000+ PSI to physically blast surfaces clean — fine for concrete, not for shingles. Soft washing uses garden-hose pressure (under 500 PSI) plus a sodium-hypochlorite-based roof cleaner that chemically kills algae, moss, and lichen. The Asphalt Roofing Manufacturers Association (ARMA) specifically recommends low-pressure cleaning with this kind of solution as the safe method for asphalt shingles.

Every 2–3 years for most asphalt shingle roofs, and every 4–6 years for metal. In Northeast Ohio, plan on the shorter end if your home is shaded by mature trees, sits near Lake Erie, or has a north-facing slope where moss and algae regrow fastest. A professional soft wash typically keeps a roof clean for 3–5 years before stains return.

Improper cleaning can void it. High-pressure washing strips the protective granules off asphalt shingles, which is one of the fastest ways to nullify both manufacturer and workmanship warranties. Soft washing — the method Wet Jet uses and the one ARMA officially recommends — is warranty-safe because it relies on a roof-safe cleaner and low-pressure rinse rather than mechanical force.

A sodium-hypochlorite-based soft-wash solution applied at low pressure, allowed to dwell 15–30 minutes, then rinsed. This kills moss at the root so it doesn't re-attach, unlike scraping or pressure washing — both of which leave live spores behind and can damage shingles. For Northeast Ohio homes shaded by mature oaks and maples, we also discuss zinc strip installation as a long-term preventive.

Not when the job is done correctly. Before we apply any cleaning solution, we pre-soak surrounding shrubs, flower beds, and grass with fresh water — which prevents them from absorbing the diluted runoff. We also tarp sensitive plants when needed and rinse everything thoroughly afterward. We've washed thousands of Northeast Ohio homes without losing a homeowner's hostas.

Most asphalt-shingle roofs take 2–4 hours start to finish, including the dwell time the cleaning solution needs. Heavily mossed roofs or large/multi-level homes can run a full day. You don't need to be home — we just need access to an outdoor water spigot and a clear driveway. Pets should stay indoors until landscaping is dry.