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BAY AREA ROOF CLEANING · SOFT WASH SPECIALISTS
Roof Pressure Washing
the safe, warranty-proof way.
Most “roof pressure washing” damages your shingles, voids your warranty, and drives up your insurance. We use the soft wash method — the only method Bay Area roofing manufacturers actually approve.
155+
5-Star Reviews
$2M
Liability Insured
9 yrs
Serving the Bay
0
Warranty Claims
Pressure washing vs Soft washing
The difference every Bay Area homeowner should know
Searching for “roof pressure washing”? Read this first — because traditional pressure washing is exactly what you don't want on your roof.
Traditional Pressure Washing
Why high pressure destroys roofs
Traditional pressure washing uses 2,000–4,000 PSI — enough to carve wood and strip paint. On a roof, that force is catastrophic.
- Strips granules off composition shingles (visible black streaks)
- Forces water under clay and concrete tile, rotting underlayment
- Loosens moss but leaves its root system, causing faster regrowth
- Voids almost all roofing manufacturer warranties
- Can raise your homeowners insurance rates or trigger non-renewal
- Costs thousands in premature roof replacement
Soft Wash (Our Method)
How we clean roofs safely
Soft wash uses low pressure (under 500 PSI) with a targeted detergent that kills moss, algae, and lichen at the spore level. The ARMA-approved method.
- Preserves shingle granules and factory finish
- Safe for composition, tile, cedar shake, and metal roofs
- Kills moss and algae at the root — no regrowth for 2–3 years
- Keeps manufacturer warranties intact
- Protects your insurance standing (no “roof damage” claims)
- Extends roof lifespan by 5–10 years
What we remove
The four things killing your roof
Bay Area moisture, fog, and tree cover make roofs a prime target. Here's what we eliminate on every job.
Black Streaks (Gloeocapsa Magma)
Those dark vertical streaks aren't dirt — they're algae colonies that feed on limestone filler in shingles.
Damage: Shingle degradation, heat retention
Moss
Green moss pads hold moisture against your roof 24/7, rotting underlayment and lifting shingles off nails.
Damage: Water intrusion, shingle failure
Algae & Lichen
Lichen is the worst — it bonds to shingle granules and requires specialized detergents to fully remove.
Damage: Permanent staining, warranty loss
Debris & Buildup
Leaves, pine needles, bird droppings, and tree sap trap moisture and create ideal conditions for regrowth.
Damage: Gutter clogs, moisture pockets
Every roof, the right way
Roof types we clean
Your roof type determines the exact method. We train on every common Bay Area roof material.
Composition Shingles
Soft WashThe most common Bay Area roof. Soft wash prevents granule loss and preserves CertainTeed, GAF, and Owens Corning warranties.
Pressure: Under 300 PSI · Chem: SH-based soft wash
Clay & Concrete Tile
Soft Wash + RinseCommon on Mediterranean and Spanish-style homes. Tiles are strong but grout and underlayment are vulnerable to high pressure.
Pressure: Under 500 PSI · Low-angle application
Cedar Shake
Gentle Soft WashNatural wood roofs common in Peninsula estates. Requires wood-safe detergents and extra care around splits and cupping.
Pressure: Under 200 PSI · Wood-safe chem
Metal & Standing Seam
Soft WashIncreasingly popular in new Bay Area builds. We use pH-neutral detergents to protect painted metal finishes.
Pressure: Under 500 PSI · pH-neutral detergent
Slate
Specialty Soft WashHigh-value estate roofs. Slate itself is tough, but flashing and mortar joints demand careful technique.
Pressure: Under 300 PSI · Joint-safe method
Flat / Low-Slope
Soft Wash + Debris RemovalCommercial and modern residential roofs. TPO, EPDM, and modified bitumen each get a tailored approach.
Pressure: Varies by membrane type
Our process
How a Miller's roof wash goes
Scheduled, explained, and done right. Most roofs finish in 3–5 hours.
1
Free inspection & estimate
Send photos or schedule a walk-through. We identify roof type, measure square footage, note trouble spots, and send a firm written quote. No surprises.
2
Property protection
Before any chemistry hits the roof, we protect landscaping, cover electrical fixtures, seal vents, and check gutters and downspouts for flow.
3
Pre-treatment
Biodegradable soft-wash detergent is applied at low pressure from the bottom up. Dwell time 10–20 minutes depending on organic growth severity.
4
Soft wash & spot treatment
Gentle low-pressure application covers every square foot. Heavy moss and lichen get hand-inspected and treated individually.
5
Rinse & gutter flush
Low-pressure rinse from the top down. Gutters and downspouts get flushed clean to handle the runoff without backup.
6
Walk-through & photo record
We do a full walk-through, document before/after, and flag any pre-existing issues (lifted shingles, flashing damage, etc.) for your awareness.
★★★★★
"Our insurance company was threatening non-renewal because of moss on the roof. Casey soft-washed it the next week and our inspector signed off immediately. Saved us thousands. He knew exactly what the insurance wanted to see."
— Google Review · Pacifica, CA
Honest pricing
What roof cleaning costs
Every quote is firm and written. These are our typical Bay Area ranges by roof size.
Small Home / Cottage
$425–$650
Up to 1,500 sq ft of roof
- Full soft wash treatment
- Moss & algae removal
- Gutter flush included
- Before/after photo record
Standard Home
$650–$1,100
1,500–3,000 sq ft of roof
- Full soft wash treatment
- Moss & algae root-kill
- Lichen spot treatment
- Gutter flush included
- Before/after photo record
Large / Estate
$1,100–$2,500+
3,000+ sq ft · complex roofs
- Full soft wash treatment
- All tile, slate, or shake detail work
- Lift or rigging when required
- Written 2-year regrowth warranty
Book direct · see our service area
Book your free roof estimate
Book online in 2 minutes, send a photo via message, or see where we work across the Bay Area Peninsula.
Book Online
Pick a date + time. Free estimate, no obligation.
Or send a quick message
We will call or text you back within the hour.
Serving the Bay Area
Based in San Mateo · 50-mile service radius.
Home baseSan Mateo, CA
Service radius50 miles
Response timeSame day
Available7 days a week
Questions we hear most
Roof pressure washing FAQ
Bay Area homeowners ask us these all the time. Straight answers.
Is roof pressure washing the same as roof soft washing?
No — and that distinction protects your roof. Traditional pressure washing uses 2,000+ PSI which strips shingle granules, forces water under tile, and voids warranties. Soft washing uses under 500 PSI with specialized detergents that kill moss and algae at the root without damaging the roof. If you see someone spraying a roof with high pressure, that is a damaged roof in progress.
Will cleaning my roof void my warranty?
Only if it's done wrong. The Asphalt Roofing Manufacturers Association (ARMA) specifically recommends the soft wash method we use. Traditional high-pressure washing does void warranties from CertainTeed, GAF, Owens Corning, and most major manufacturers. We provide written documentation of our method if your manufacturer asks.
How often should I have my roof cleaned in the Bay Area?
Most Bay Area roofs benefit from a cleaning every 2–3 years. Homes under heavy tree cover, on the coast (Pacifica, HMB), or with north-facing exposures often need it every 18–24 months. If you see black streaks, green moss patches, or lichen growth, you're due.
My insurance company flagged my roof — can you help?
Yes, this is one of our most common calls. Insurance carriers increasingly require moss and algae removal before renewal. We provide documentation suitable for your inspector and can typically schedule within 3–7 days. We work with customers of State Farm, Allstate, Farmers, USAA, Liberty Mutual, and the CA FAIR Plan.
How long does the cleaning last?
Our soft wash kills moss and algae at the spore level, which prevents regrowth much longer than pressure washing. Most customers see 2–3 years of clean roof from a single treatment. We also offer optional annual maintenance plans to keep it clean longer.
Is the detergent safe for pets, plants, and the environment?
Yes. We use biodegradable soft wash chemistry specifically formulated to be safe for pets, plants, and the environment once diluted and rinsed. We pre-rinse landscaping with fresh water, apply at the correct dilution, then do a full post-rinse. In 9 years and 1,400+ jobs, zero plant damage claims.
Do you service commercial properties and HOAs?
Yes — apartment complexes, HOAs, office buildings, and commercial roofs. We carry $2M general liability and provide COI on request. See commercial services ›
What if my roof has lifted shingles or damage?
Full walk-through before we start. If we find lifted shingles, damaged flashing, or other issues, we document them and let you know before cleaning. Some damage needs repair first — we'll refer you to a trusted local roofer rather than making it worse.
Ready for a roof that looks brand new?
Free, firm estimates. Same-day response. 9 years, 155+ five-star reviews, zero warranty claims. Your roof is in good hands.