What Should a Roof Soft Wash Quote Include
You have got three roof cleaning quotes spread out on the kitchen table. One says $375 flat. One says $620 with a paragraph of fine print. The third is $890 and includes a breakdown that runs to half a page. Same roof. Three companies. A $515 spread.
You read them all twice. None of them make it obvious what you'd actually be paying for.
That's the problem with most roof soft wash quotes. They give you a number. They don't give you the work.
A good quote is a contract about what's going to happen on your roof — the method, the chemistry, the protection for the rest of your property, the warranty status when the truck pulls away. Once you know what should be in writing, the price spread starts making sense. And the cheap quote usually stops looking cheap.
Why the prices vary so wildly on the same roof
Two companies pricing the same 2,200-square-foot roof can land $400 apart for a real reason: they're not doing the same job. The cheap quote is almost always a fast pressure rinse with a degreaser, in and out in 45 minutes. The high quote is a proper soft wash — proper chemistry, proper dwell time, proper rinse — plus plant and yard protection, photo documentation, and a written kill-rate guarantee.
You can't tell the difference from the number. You can only tell from what's listed below the number.
The other reason prices vary: square footage math. A 2,000 sq ft footprint home has roughly 2,800 sq ft of actual roof surface once you factor in pitch and overhang. Some companies quote off footprint and absorb the difference. Some quote off measured roof surface. Same job, different math, different number on the line.
A quote that doesn't tell you how square footage was calculated isn't really a quote — it's a guess priced as a fact.
The line items a complete roof soft wash quote should spell out
Here's what should be in writing before you sign. If a line is missing, ask. If the company can't explain it, that's the answer.
| Line item on a complete quote | What it tells you | What's wrong if it's missing |
|---|---|---|
| Measured roof surface area, pitch, and material | Pricing matches the actual job, on the actual roof type | A flat number with no scope is a flat number with no accountability |
| Cleaning method spelled out: "low-pressure soft wash" | No pressure washer hitting the shingles | High-pressure rinse damages granules, voids warranty |
| Biocide active ingredient and target concentration | Sodium hypochlorite at the right percentage to kill algae cells | Too dilute = surface rinse only; too strong = plant damage |
| Dwell time before rinse | The kill happens during dwell, not during rinse | Skipped dwell = colonies regrow in months |
| Plant and yard protection plan | Plants, shrubs, sod will be pre-wet, tarped, and post-rinsed | Bleach runoff kills hostas, hydrangeas, sod within a week |
| Gutter and downspout flush after wash | Dead algae and shingle debris cleared from the gutter line | Sludge sets up in the gutter trough, blocks downspouts |
| Insurance coverage and liability limits | Crew has GL and workers' comp before they're on your roof | One slip and the homeowner's policy gets the claim |
| Manufacturer-compliant method statement | The wash follows ARMA-style soft wash guidelines | Pressure or wrong chemistry can void the shingle warranty |
| Photo documentation before and after | Proof the colonies were killed and the surface is clean | No baseline if you need to dispute results |
| Written warranty on streak return | If algae streaks come back inside the warranty window, they re-treat | "Looks clean today" is not the same as "stays clean" |
A complete quote covers every row in that table. A bad quote covers two or three and quietly leaves the others up to whatever happens on the day.
How square footage should be calculated
A roof is not a flat surface, so the math matters.
Footprint is the area of the house seen from a bird's-eye view — the rectangle of the foundation. A 40-foot by 30-foot ranch has a 1,200 sq ft footprint. The actual roof surface is bigger because the roof has a pitch (it's tilted up) and an overhang (it extends past the wall).
A standard 6/12 pitch roof has about 1.12 times the area of the footprint. An 8/12 pitch is closer to 1.20. A 12/12 steep roof can hit 1.42. Add eight inches of overhang on all sides, and that 1,200 sq ft footprint becomes a 1,400 to 1,700 sq ft cleaning surface, depending on the pitch.
The companies that price off footprint and don't say so are hiding the math. The problem comes when the homeowner asks for an itemized invoice later and finds out the "$0.25 per sq ft" rate was applied to a number that doesn't reflect what the crew actually walked.
Two other variables belong in the same section: stories and roof material. A two-story home runs higher per square foot than a single-story ranch because ladders, fall protection, and reach equipment add labor. Asphalt shingle is the easiest to soft wash. Tile, slate, wood shake, and metal each have their own method tweaks — concentration, dwell time, rinse pressure — and a quote that doesn't name the surface is written for "a roof," not yours.
Ask directly: "Is this priced on footprint or measured surface, at what rate per square foot, and adjusted for stories and roof material?" Any company that does this work for a living can answer in two sentences.
What should be in the biocide section of the quote
The chemistry is the work. Everything else is logistics.
A roof soft wash works because sodium hypochlorite — bleach, basically — kills algae cells at the cellular level. Mixed with a surfactant so it clings to the shingle long enough to penetrate the colony, applied at low pressure so the soft wash tip doesn't dislodge granules, allowed to sit for 10 to 20 minutes of dwell time, then rinsed off with a soft stream.
The quote should name the active ingredient (sodium hypochlorite), give a working concentration range (most reputable companies land somewhere between 2% and 4% at the nozzle), and specify the dwell time before rinse. It should also note the surfactant or "cling" additive used to extend contact time on the sloped surface.
If the quote just says "eco-friendly cleaning solution" with no chemistry behind it, you're looking at one of two things: a heavily diluted bleach mix that won't kill the colony, or a non-bleach product that has to be reapplied every six months and costs you more in the long run. The Asphalt Roofing Manufacturers Association — ARMA — has been clear for over a decade that sodium hypochlorite is the cleaning agent that works on Gloeocapsa magma. Anything else is a workaround.
A quote that lists actual chemistry isn't being technical for fun. It's giving you the evidence you'd need if a shingle issue came up later and the manufacturer asked how the roof was cleaned.
Plant and yard protection — the part nobody asks about until something dies
Bleach kills algae. It also kills plants.
A proper soft wash quote should describe, in writing, how the crew will protect the plants and yard below the roof. The standard protocol has three parts: pre-wet all shrubs, sod, and flower beds within 15 feet of the house with plain water before any product touches the roof; tarp or bag the most sensitive plants — hostas, hydrangeas, ferns, anything broad-leaf and thirsty; and post-rinse the same plants and the soil at their base immediately after the roof rinse is done.
A quote that doesn't mention plant and yard protection is hoping you don't ask. Then you find brown hydrangeas in two weeks, and the company doesn't return your calls.
The most common damage from a soft wash done without protection isn't a single dead plant. It's a strip of dead sod two feet wide running the perimeter of the house where the bleach-laden rinse came off the roof and pooled at the foundation. You'll see it three to four weeks after the job. By then the lawn replacement is on you.
Insurance, license, and warranty status
Three things that should be on the quote in plain language.
General liability insurance — a real coverage limit with a real carrier, not "fully insured." Workers' compensation for everybody on the crew. A certificate of insurance available on request, with your address listed as the work site.
License or registration status. Power washing isn't licensed at the state level the way electrical or plumbing is, but the business itself should be registered in the state, and the crew should be employees, not subcontractors with no paper trail.
Warranty status of the shingles. The quote should state the method conforms to the manufacturer's published cleaning guidelines — low-pressure chemical wash, not high-pressure water blasting. A company that pressure washes a roof and voids the warranty leaves you holding a roof that has years cut off its rated life with no recourse.
This is the part of the quote that gets skipped. It's also the part that costs the most if something goes wrong.
Red flags — what a roof soft wash quote should not contain
If you see any of these in writing, push back before you sign.
A quote with the phrase "pressure washing your roof" instead of "soft washing." Pressure on the shingles strips granules. Most major manufacturers — GAF, CertainTeed, Owens Corning — explicitly warn against high-pressure cleaning. A roof under pressure is a roof aging twice as fast.
A quote with no chemistry listed and no dwell time. That's a rinse, not a wash. The algae will be visibly back within a season.
A quote that bundles "roof cleaning" with house wash and gutter cleaning at one combined price with no line breakouts. Bundles can save money — but only if you can see what each piece costs and what each piece includes. A flat bundle hides the corners that got cut.
A quote with no warranty language at all. Any company doing real soft wash work should be willing to put their results in writing for at least one year, sometimes longer, on roofs with good sun exposure. A company that won't warranty their work doesn't trust their own method.
A "today only" price that drops $200 if you sign right now. The job doesn't change because you signed faster. The price drop is the company telling you the original number had room to come down — which means it had room to come up, too.
How to compare three quotes without getting lost
Pull the three quotes side by side. Make a single sheet with the line items from the table above down the left and the three companies across the top. Fill in what each one actually says.
You'll see it fast. The cheap quote has empty cells where the others have detail. The expensive quote fills more rows, sometimes in more depth than you want — but you'll know what you're paying for. The row-by-row picture tells you whether the gap to the high quote is real value or padding.
The cheap quote isn't cheap if the algae is back in six months. The expensive quote isn't expensive if it adds three or four years to the life of the shingles.
Frequently Asked Questions
The quote is the job, in writing, before anyone gets on the roof
A roof soft wash quote isn't a price tag. It's a description of the work — the method, the chemistry, the dwell time, the yard protection plan, the insurance, the warranty. The price at the bottom is the consequence of all the rows above it, not the headline.
Read the rows. Compare the rows. Sign the quote that tells you the whole story.
The one that just gives you a number is the one most likely to leave you with streaks back next spring and a dead row of hostas to replant.
Superior Power Washing soft washes asphalt shingle roofs across Waldorf, MD, and all of Charles County and Southern Maryland — including Upper Marlboro, Accokeek, Clinton, Fort Washington, and Prince Frederick. Cedric provides itemized written quotes with measured roof surface, sodium hypochlorite chemistry, dwell-time spec, full plant and yard protection, manufacturer-compliant low-pressure method, and a written warranty. Owner-operated, fully insured. Call (240) 901-4252 for a free on-site assessment.
