How To Use a Pressure Washer

DEAR TIM: I want to rent a pressure washer to clean any number of things around my home. I intend to clean my composite deck, my patio, my driveway and wash down my house that has a combination of wood and vinyl siding. I’ve never used one before. Are they hard to use? Can you share some tips so I don’t hurt myself, my husband, my pets and my house? Peggy M., San Jose, CA

DEAR PEGGY: I’ve used pressure washers for years, and I'm here to tell you they're magnificent tools. When used to clean things that can withstand the pressure and power from the tip of the wand, they're enormous time savers. The famous line from the movie Spiderman, "With great power comes great responsibility.", describes much of what you need to know.

I actually don't think many people realize the enormous force that's generated at the tip of the wand where the water spray exits. Depending on the power of the machine you rent and the tip you use, the water stream can etch and erode concrete. That should help you understand what it can do to human or animal tissue, composite decking, wood, vinyl or any other material that's softer than concrete.

In other words, you must have a healthy respect for the machine and what it's capable of doing to you, your pets or your possessions. I can tell you that I'd spend the first 15 minutes testing out what the machine does on things you're going to throw away.

It's vital that you keep pets indoors so they don't think the spray wand is a play toy. My dog loves to play in water and thinks that the pressure washer is a great thing to be around. Not only is the sound from the gas engine hard on her hearing, the spray from the want could blind her or cut into her skin in less than a second. The same holds true for you and your husband. Never point the wand at an animal, human or plant.

You need to wear safety glasses or even goggles for full eye protection. The blast of water aimed at a driveway or patio edge can shoot up sand, rocks or dirt directly into your face. Paint chips from siding can fly into your face. This happens without warning. If you rent a gas-powered machine, wear ear muffs or great ear plugs.

Be sure you understand how the machine works. Many pressure washers depend on the incoming water from the garden hose to cool the pump that creates all the pressure. If you have the pressure washer on, but no water is flowing through the wand, you can damage the pump. Read the owners manual or any quick-start guide the tool rental business provides.

New pressure washers typically come with an assortment of tips for the wand. These can range from 0 degrees up to 40 degrees. The lower the number, the more concentrated and dangerous is the spray of water. I would start cleaning the house siding with a 40-degree tip to see if it achieves what you want. You'll probably have to use a 25-degree tip to get good results.

Never aim the spray wand up as you clean siding or aim it at cracks where siding butts up against windows, doors or any trim boards. You can drive water deep into these cracks and cause leaks or damage to your home. Never aim it at vinyl siding overlap seams such that the water stream gets behind the siding.

Remember, siding is installed knowing that Mother Nature's rain aims down not up. In rare instances rain may be horizontal, but almost never does rain blow hard in an upward fashion. It can happen because of the shape of roofs and dormers during violent wind storms or hurricanes, but it's not normal.

The last time I cleaned my own composite deck with a pressure washer, I damaged it. I was fatigued and not paying attention. I was also in a rush. For about one second, I got the tip too close and it sliced into the deck board. It's impossible to repair that damage. It's a good thing it's in an out-of-the-way place that I can hide with a few potted plants.

It only took two seconds to cause this damage to the composite decking. Photo Credit: Tim Carter

Realize that pressure washers can readily peel paint from just about any exterior surface. If you want to use it for this purpose, hold the spray wand so the stream of water attacks the paint at a very low angle. The spray wand would be nearly parallel with the painted surface.

Never allow children to play with a pressure washer. These machines should be in the same category as handguns or rifles. They're that dangerous when it comes to children and what harm can result if this tool is misused.

You can watch a video showing you the components of a pressure washer and how to use it at www.AsktheBuilder.com. Simply type "pressure washer video" into the search engine.

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