· by Michael Blair, Nashville's Pressure Washing
A pressure washer is easy to buy or rent, and knowing what each surface on a house will tolerate takes far longer to learn. A few specific questions separate a contractor who understands surfaces from one who owns a machine, and the answers tell you more than the price does.
Ask about method per surface
Ask what pressure and what solution they use on siding, on brick, on concrete and on the roof. On our own jobs the answers differ: house washing is a low-pressure soft wash with a cleaning solution, while driveway and concrete cleaning is where real pressure belongs. Someone who gives you one answer for all four surfaces has told you something.
The roof is the clearest test. We never take a pressure wand to asphalt shingles; roofs get a soft wash, and our post on why roof washing is never done with pressure explains the method. A company that plans to pressure wash your shingles is not one we would let up there.
Ask about plants and water
Ask how they protect the beds around the house. We soak the plantings with plain water before any solution goes on and rinse them again when we finish, and any crew should be able to describe what they do. Then ask where the runoff goes, particularly where the yard slopes toward a neighbor or a storm drain. Metro Water Services’ guidance for businesses and property owners says dirty pressure washing water must never be let into a storm drain, calls it illegal, and says a property owner can be fined for dumping wash water. The city’s stormwater page explains why: unlike sewage, runoff gets no treatment before it reaches the environment. Our post on where wash water goes in Nashville covers how a crew keeps it out of the drain.
Ask whether they need access to your water and electricity, and whether that is factored into the price.
- Different method per surface, named
- Soft washing for the roof, never pressure
- Plants wetted before and rinsed after
- A plan for where the runoff goes
- Liability insurance certificate sent by their agent
- What is and is not included in the quote
Why does insurance matter so much for house washing?
House washing puts people on ladders, sometimes on roofs, and near the overhead line that feeds many houses. OSHA’s fall protection page says falls are among the most common causes of serious work-related injuries and deaths, and OSHA’s page on electrical hazards lists contact with power lines first among the most frequent causes of electrical injuries. Pressure in the wrong place can also damage the house itself, which our post on what pressure washing can permanently damage goes through surface by surface.
Ask for a certificate of liability insurance sent to you by their insurance agent rather than a copy from the company’s files, and check that its dates cover the day of the job. If the company says it holds a state contractor’s license, Tennessee’s Board for Licensing Contractors, which licenses general and home improvement contractors under Title 62, Chapter 6 of the Tennessee Code, has a Verify a License search that will confirm it.
Roof work adds another layer. Ask whether their policy covers it and how they reach the roof. We work from the eave and a ladder where we can and keep our feet off the shingles as much as the job allows.
What should a pressure washing quote include?
Whether gutters are washed on the outside only or also cleared out inside. Whether the driveway and walks are included or priced as extra. Whether a post-treatment goes on after the wash, and if it does, what the product is and what the company says it does.
In our experience those three are where quotes that look alike usually part ways. Our pressure washing guide covers what washing costs in Nashville, and when you ask us for a free estimate, tell us which of the three you want included.
Sources
- Metro Nashville Water Services, Commercial and Industrial Guidance — Never let dirty pressure washing water enter the storm drain; it is illegal and can be fined; a business or property owner can be fined for dumping wash water
- Metro Nashville Water Services, Stormwater — Stormwater receives no treatment before it is released into the environment
- OSHA, Fall Protection — Falls are among the most common causes of serious work-related injuries and deaths
- OSHA, Electrical — Contact with power lines is among the most frequent causes of electrical injuries
- Tennessee Department of Commerce & Insurance, Board for Licensing Contractors — Licenses general and home improvement contractors under Tennessee Code Annotated Title 62, Chapter 6; Verify a License search
FAQ
What to Ask a Pressure Washing Company — questions
How much should house washing cost?
We price each house on its size, its number of stories, what it is clad in and how easy it is to reach, so the useful comparison between two quotes is what each includes rather than the total. When two quotes are far apart, check whether concrete, gutters and a post-treatment are in both, and whether one plans to soft wash the roof while the other leaves it alone.
Should the company use my water?
It depends on the company. Some run from an outside spigot and some bring water in a tank on the truck. Either is fine as long as the quote says which, and there is a working outside faucet within reach if they need one. A home on a well or with low water pressure is worth mentioning when you ask for the quote.
What is the single best question to ask?
Ask what they do differently on a roof compared with a driveway. Anyone who says both get pressure washed is planning to put a wand on your shingles, which we never do. A contractor who describes a soft wash for the roof and real pressure for the concrete is thinking about the surface in front of them.
Are pressure washers dangerous?
They can be, because of where the work happens: on ladders, sometimes on roofs and near the overhead line that feeds the house. OSHA counts falls among the most common causes of serious work injuries and deaths, and lists contact with power lines first among frequent causes of electrical injuries. Pressure aimed wrongly can damage the house itself.