How to choose a pressure washing company in Pennsylvania

Updated · KeystoneProGuide editorial team

What matters most when choosing a pressure washing company?

Two things above all: that the company is properly registered and certified for your house, and that it plans to clean each surface in the way that surface's own guidance allows. Price comes after both. A cheap wash at the wrong pressure can damage the surface of a deck, push water behind siding or scar old brick, and the sources below say so in plain terms.

Is the company registered with the state?

Pennsylvania has no license for washing, but its home improvement registration is the one public check most companies can be held to. Ask for the registration number, which appears as PA followed by digits, and look it up in the Attorney General's contractor search. Its list of work types includes "Pressure Washing", though the page notes that the field is new and incomplete. Whether a company that only washes must register is a question the law's wording does not settle; what Pennsylvania requires sets out what it does and does not say.

A registration is not a seal of quality. The Attorney General says it is not an endorsement of a contractor's honesty or quality, and advises you also to check references, get more than one bid and look for complaints with the Better Business Bureau.

Does your house need a lead-safe certified firm?

If it was built before 1978 and the company will wash painted siding, trim, porches or fences, it very likely does. The U.S. Environmental Protection Agency (EPA) requires anyone paid to disturb painted surfaces in such a home to be certified in lead-safe work practices, and it says this covers all firms, even sole proprietorships. The EPA keeps a search for lead-safe certified contractors on its program page.

Ask how the company will contain the work. The EPA's archived answer on this point says washing must keep dust and debris, including what is in the waste water, inside the work area.

Does the company's method suit your surfaces?

Ask how it will clean each surface, and compare the answer with what the people who make or care for that material say.

  • Asphalt shingle roof. The shingle makers' trade association, ARMA, says not to use a power washer, brush or broom, and that high-pressure washing is likely to damage asphalt roofing. It describes a bleach solution applied gently, left for 15 to 20 minutes and rinsed with a gentle spray. ARMA also encourages using professionals, since the process makes a roof slippery.
  • Vinyl siding. The siding industry's association, PEPA, says a power washer can be used with caution, held straight at eye level, because aiming upward can force water behind the panels. It adds that some siding makers do not recommend power washing at all and others set limits on pressure and cleaners, so the right answer depends on your siding.
  • Old brick and stone. The National Park Service says spraying should be done by professionals who understand pressures and standoff distances, with a low-pressure spray of 100-400 psi and the wand at least 12 inches from the surface. It warns that most power-washing equipment sold in hardware stores runs at 1600-3200 psi, which it calls potentially damaging.
  • Wood decks. A chemist at the U.S. Forest Service's Forest Products Laboratory advised letting the cleaner do the work, saying that using a power sprayer can do damage to the surface that later makes it hard for a finish to soak in.

A company that names one pressure for everything, or plans to use full pressure on a shingle roof, is telling you something worth knowing.

What will it spray on your house?

Ask for the product names and read the labels. Products sold to kill mold, mildew or algae are likely to be pesticides under the federal definition the EPA applies, and Pennsylvania's Department of Agriculture requires a commercial applicator license to use pesticides on another person's property. Ask which license the company holds if it proposes one.

Ask too how it protects your plants and what it does with bleach. ARMA tells people applying its bleach solution to avoid damaging the surrounding landscape. The EPA warns never to mix chlorine bleach with cleaners that contain ammonia, because toxic fumes could be produced.

Where will the wash water go?

A good answer names a plan: where the water will drain, and what happens to it if the job involves old paint, oil or chemicals. The EPA tells firms washing pre-1978 painted surfaces to dispose of the waste water properly and to check with the local water authority. Separate storm sewers in Pennsylvania carry water to streams without treatment, so "down the drain" is not an answer.

Does trade certification count?

It is one more piece of information, not a license. Power Washers of North America, a trade association, runs a house wash certification that it says teaches low-pressure washing methods, chemical handling and how to avoid damage to siding, windows and plants. In its own words, certification is not legally required and does not claim perfection or guarantee results. Treat it as evidence of training, and still make the other checks.

How do you compare companies on price?

  • Get written estimates from more than one. The Federal Trade Commission (FTC) says an estimate should describe the work, materials, completion date and price, and it advises against automatically choosing the lowest bidder.
  • Make the scopes match. Surfaces, square footage, method, chemicals, rinse and cleanup should be the same on each quote before the totals mean anything. The cost guide sets out how companies price.
  • Check insurance. The FTC suggests asking for proof of insurance. Registered home improvement contractors must carry at least $50,000 each of personal injury and property damage coverage.
  • Be wary at the door. The FTC lists contractors who knock because they are in the area, press for an immediate decision or ask for full payment up front among the signs of a scam.

Businesses that offer the service are listed on the pressure washing directory page.

Sources

  1. Home Improvement Contractor Search, Pennsylvania Office of Attorney General
  2. Home Improvement Contractor Verification, Pennsylvania Office of Attorney General
  3. Frequently Asked Questions: Home Improvement Contractor Registration, Pennsylvania Office of Attorney General
  4. Lead Renovation, Repair and Painting Program, U.S. Environmental Protection Agency
  5. How do RRP requirements apply to pressure washing? What containment and other preparation are required?, U.S. Environmental Protection Agency (January 2025 archived copy)
  6. Algae Discoloration of Roofs, Asphalt Roofing Manufacturers Association (ARMA)
  7. How to Clean Vinyl Siding, Polymeric Exterior Products Association (PEPA)
  8. Preservation Matters: Maintenance - Graffiti Removal from Historic Features, National Park Service
  9. Springtime Means Deck Maintenance for Many Homeowners, USDA Forest Service, Forest Products Laboratory (news release via Newswise)
  10. Types of Pesticide Ingredients, U.S. Environmental Protection Agency
  11. Pesticide Applicators, Registered Technicians, and Certification Exams, Pennsylvania Department of Agriculture
  12. A Brief Guide to Mold, Moisture and Your Home, U.S. Environmental Protection Agency
  13. What is an MS4?, Penn State Extension
  14. House Wash Certification Training, Power Washers of North America (PWNA)
  15. How To Avoid a Home Improvement Scam, Federal Trade Commission

Find Pressure Washing businesses

Pressure Washing in Pennsylvania

More Pressure Washing guides

All Pressure Washing guides