Pressure washing can effectively clean outdoor surfaces, however, it’s not a one-size-fits-all solution. Using high-pressure water on the wrong materials can cause serious damage. Whether you’re a homeowner or a property manager, it’s important to know what surfaces can handle a pressure wash — and which ones need gentler cleaning methods. 

Surfaces That Can Be Pressure Washed

Concrete and Asphalt Driveways 

Concrete and asphalt surfaces are durable and can withstand high-pressure cleaning. You’ll be able to effectively remove oil stains, mildew and mold, grime, and embedded dirt, making driveways look new again. It can also help prepare these surfaces for painting, sealing, or staining. 

Brick and Stone Patios

You can safely pressure wash unsealed brick and natural stone to remove grime and moss. However, be cautious with mortar joints, especially if they’re old or crumbling; you may need to use lower pressure, around 1000 to 15000 PSI.

Vinyl Siding

When pressure washing vinyl siding, use moderate pressure, a wide spray nozzle, and keep the wand at a safe distance to avoid cracking or forcing water behind the siding panels. You may want to test the pressure and nozzle on a hidden spot to ensure no damage occurs.

Wood Decks and Fences

You can pressure wash wood as long as you exercise caution so as not to splinter it, create new scratches, or cause it to become fuzzy. Use lower pressure and a wide nozzle to avoid splintering or etching the surface. Softwood, in particular, is prone to damage. 

Outdoor Furniture (Plastic and Metal)

Plastic chairs and metal patio sets can handle pressure washing, especially when removing built-up grime and bird droppings. Use low or moderate pressure and a fan spray, which helps spread the water stream, reducing the risk of damage. 

Garages and Workshop Floors

Garage and workshop floors often accumulate oil, paint, and dirt. You can use pressure washing to deep-clean garage floors, especially when combined with a degreasing agent. Be mindful of drywall, particularly if it’s not sealed. If you’re worried, cover it with a tarp or sheet. 

Surfaces That Should Not Be Pressure Washed

Roof Shingles (Especially Asphalt)

Pressure washing can loosen shingles, remove granules, damage the roof itself, and lead to leaks. If you need to clean your roof, use soft washing methods with a mild detergent. This will effectively remove dirt, moss, and mildew without damaging roofing material. 

Old or Weathered Wood

Older wood may be too soft and brittle to handle any level of pressure washing without damage. Hand cleaning or soft washing is safer and more effective.

Windows and Glass Panels

High-pressure water can shatter glass or damage seals, especially if the windows are older or delicate. Use a soft brush or squeegee with a glass-safe cleaner for a streak-free finish. 

Electrical Panels and Outdoor Fixtures

Never mix water with electricity. Keep pressure washers away from meters, panels, electrical outlets, and outdoor lighting to prevent electrical hazards and fire risk. If you want to clean around electrical fixtures, consider hiring a professional. 

Painted Surfaces (Unless You’re Removing Paint)

Keep your pressure washer away from painted surfaces, unless you’re trying to strip the paint. High-pressure water can cause peeling, chipping, or an uneven finish on painted surfaces.

Vehicles (Without Proper Settings)

While some car washes do use pressure, a home pressure washer might be too powerful and damage your car’s paint or trim. If you want to use your pressure washer to clean your car, use the proper low-pressure nozzles. 

Pressure Washing Tips 

Here are a few tips if it’s your first time using a pressure washer:

Prep the Area Properly — Clear the area you are going to pressure wash of any debris, protect plants with tarps, and cover fixtures and electrical outlets. 

Use Detergent Wisely — Dilute detergent according to the manufacturer’s instructions and avoid excessive foaming, which can damage the pump. 

Understand Nozzles — Use the proper nozzle, as every nozzle produces different spray patterns and pressures. A wider spray will be more gentle, while a narrower spray will be more powerful. 

Keep a Good Distance — Start with a distance of one to two feet from the surface and gradually move closer as needed, and if the material can handle it. 

Use Your Pressure Washer Wisely 

Pressure washing can effectively clean and refresh a variety of surfaces, but it’s not suitable for everything. Using the wrong pressure or technique on delicate materials can lead to costly damage. By understanding which surfaces can handle a pressure wash and which ones can’t, you’ll get better results and protect your property. When in doubt, start with a lower pressure setting or call in the professionals to ensure a safe and effective clean.