Exterior cleaning has almost no barrier to entry. A machine, a truck and a phone is the whole startup cost, which means the range of competence in this trade is enormous — and the difference does not show up in the quote.

These are the questions worth asking. Ask them of us too.

1. "Are you insured, and can I see the certificate?"

The only genuinely non-negotiable one. General liability covers damage to your property — a blown window seal, water in a wall cavity, a stripped roof.

Good answer: yes, and here is the certificate, unprompted.
Bad answer: "we're careful" or "we've never had a claim". Neither is insurance.

2. "What pressure will you use on my siding and roof?"

The question that separates people who understand surfaces from people who own a machine.

Good answer: a number — under 300 PSI for siding, under 100 for a roof — plus the phrase soft wash and an explanation that the solution does the work.
Bad answer: "whatever it takes to get it clean", or any number above about 500 PSI for either.

3. "What do you do about my plants?"

Tests whether they have a method or just good intentions.

Good answer: soak the beds first, cover what needs it, rinse as we go and again at the end.
Bad answer: "they'll be fine."

4. "What exactly is included?"

The most common source of disappointment. A house wash to one company means walls only; to another it includes soffits, eaves, gutter faces, exterior light fixtures and the front door surround.

Good answer: an itemised list you can read.
Bad answer: a single number and a handshake.

5. "What happens if a stain does not come out?"

Tests honesty directly, because the true answer is always "some things will not fully clear".

Good answer: a specific breakdown — this will clear, this will lighten, this will probably shadow.
Bad answer: "everything comes out."

6. "Have you worked on a property like mine?"

A 1912 wood-frame home in Riverside, a tile roof in Ponte Vedra, coquina in St. Augustine and a well-water property in Middleburg are four genuinely different jobs.

Good answer: specifics about what that property type needs.
Bad answer: "it's all the same really."

7. "When will you seal, after cleaning the pavers?"

Only relevant if sealing is quoted, and it is the fastest way to identify a corner-cutter.

Good answer: a separate visit, 24 to 72 hours later, once they are properly dry.
Bad answer: "we can do it all today." That is how pavers end up cloudy, and stripping costs more than the original job.

8. "Can I see reviews, and are they recent?"

Look for specificity rather than volume. A review naming the neighbourhood, the surfaces and the crew member reads very differently from five words of praise.

Be sceptical of a company whose reviews all arrived in the same fortnight, and of any site displaying testimonials with no source attached to them.

Three quiet warning signs

  • A quote given without seeing the property or photos. That is an opening bid, and it will change on the day.
  • Pressure to decide immediately. Exterior cleaning is never urgent enough to justify a deadline.
  • A price dramatically below everyone else. Ask what is being left out. Usually it is the insurance, the dwell time, or the plant protection.

And one thing that is not a warning sign: being told a job does not need doing yet. That is a contractor behaving well.