The fastest way to filter a pressure washing company is to ask whether they'll soft wash your siding or pressure wash it, and why. Someone who can answer that clearly, unprompted, is almost always competent at the rest. Someone who talks about PSI and "blasting it right off" is offering you a result that lasts eight weeks and a real chance of damage.
Below: the nine questions, why insurance is the one to actually verify, the method questions that reveal skill, quote red flags, why the cheapest bid costs more, and a checklist you can work through on the phone.
The nine questions
- Are you insured, and can you send the certificate from your insurer? Not a forwarded PDF — from the insurer.
- Will you soft wash or pressure wash my siding? The answer should be soft wash, with a reason.
- What's in your cleaning solution? Any competent company will tell you: diluted sodium hypochlorite and a surfactant.
- How do you protect my plants? The answer is pre-wetting with clean water before and after. If they say "we're careful", that's not a method.
- Is this a fixed price or an estimate? Fixed, in writing, before booking.
- What's not included? The most revealing question on the list.
- How do you handle rust and oil stains? They should describe different chemicals, not more pressure.
- Who actually does the work? Employees or subcontractors — and are the subs covered by the same insurance?
- When do I pay? On completion, after you've inspected it, for standard residential work.
Insurance: the one to verify
Most people ask "are you insured?", hear "yes", and stop. That question has never once produced a "no".
You want two policies, and you want to see them:
- General liability, minimum $1,000,000. This covers damage to your property — a blown window seal, water forced into a wall, a cracked tile. Repairs from a bad wash routinely run into thousands.
- Workers' compensation. This is the one people miss and it's the one that matters most to you. If an uninsured worker falls off a ladder on your property, the claim can come back to your homeowner's policy. In a trade that involves ladders, roofs and chemicals, that's not a remote risk.
Ask for the certificate of insurance to be sent by the insurance agent directly. It takes them one email, it's a completely normal request, and a company that finds it awkward has told you something.
Florida doesn't issue a specific state pressure-washing licence, so licensing tells you less here than insurance does. Companies should hold a local business tax receipt. Treat missing insurance as disqualifying regardless.
Method questions that reveal skill
These are the ones that separate people who own equipment from people who understand surfaces. You're not testing them — you're listening for whether they think about it at all.
| Question | Good answer | Warning sign |
|---|---|---|
| Siding method | Soft wash under 500 PSI, solution kills at the root | "We'll blast that off, 4,000 PSI" |
| Roof method | No-pressure soft wash, under 100 PSI | Any mention of pressure washing shingles |
| Driveway tool | Rotary surface cleaner for the open slab | Wand only — expect stripes |
| Plant protection | Pre-wet before, rinse after | "We're careful around them" |
| Rust staining | Oxalic-acid treatment, separate line item | "That'll come off with the pressure" |
| How long results last | 18–24 months on a soft wash | Vague, or an unrealistic guarantee |
The roof one is genuinely disqualifying. The Asphalt Roofing Manufacturers Association specifies a chemical clean with a low-pressure rinse, and most shingle warranties are void if a pressure washer has been used. Anyone offering to pressure wash your roof either doesn't know that or doesn't care. See our roof cleaning guide for the detail.
Quote red flags
- Payment in full up front. Not the norm for residential work. A deposit on a large sealing job where materials are bought in advance is reasonable; the whole amount isn't.
- "Estimate" rather than a fixed price. Estimates grow on the day.
- Pressure to decide today. Legitimate companies have a schedule, not a closing technique.
- No written scope. If it doesn't list surfaces and storeys, you can't hold anyone to it.
- Door-knocking with a van and no online presence. Not always a problem, but verify the insurance before anything else.
- A guarantee that sounds too strong. "Stains gone or your money back" — nobody can promise a five-year-old oil stain will fully lift. Realistic answers are a good sign.
Why the cheapest quote costs more
A quote well below market usually isn't a better deal, it's a different job. What's typically missing:
| Omission | Saves them | Costs you |
|---|---|---|
| Pressure instead of soft wash | Chemicals and dwell time | Regrowth in 2–3 months; possible damage |
| No insurance | $2,000–$6,000 a year | Your policy covers their mistakes |
| Wand instead of surface cleaner | Equipment cost | Striped driveway; re-clean to fix |
| No rust or oil treatment | Chemicals and 30 minutes | The stains you most wanted gone, still there |
| Ground floor only | Setup and time | Half a clean house |
| No plant pre-wetting | 20 minutes | Damaged planting |
Get two or three quotes, but compare them on scope. Ask each company to list what's included, then put the lists side by side. Half the time the "expensive" quote is the only one covering the whole house. Our Jacksonville price guide has the per-square-foot rates so you can check where each bid sits.
The hiring checklist
Work through this on the phone. It takes about five minutes.
- Certificate of insurance requested from the insurer — general liability and workers' comp
- Confirmed soft wash on siding, stucco and roof
- Confirmed surface cleaner on concrete
- Solution described plainly and plant pre-wetting confirmed
- Fixed written price, with exclusions listed
- Rust and oil treatment quoted separately if you have those stains
- Confirmed who does the work, and that subs are covered
- Payment on completion
- Two references at similar properties — and one actually called
My honest take
We're a pressure washing company writing about how to choose a pressure washing company, so take this with the appropriate scepticism — but the advice above is what I'd tell my own family, and some of it costs us work.
The most useful thing you can do isn't to grill anyone. It's to notice whether they explain things without being asked. Someone who tells you unprompted that your driveway needs a rust treatment but your fence really doesn't need cleaning this year is showing you how they'll behave once they've got your money. Someone who agrees enthusiastically with everything you suggest is showing you something else.
And a small thing that predicts a lot: ask what happens if it rains. A company that says "we'll reschedule" has a functioning schedule and standards. A company that says "no problem, we work through it" is telling you they can't afford a lost day — which is exactly the pressure that leads to pavers being sealed while they're still damp.
If you'd like to try these questions on us, get in touch — or read what we actually do on the main pressure cleaning page and our about page first.
