Updated January 1, 1 . AmFam Team
Want to blast away dirt and grime? Pressure washing is a solution for cleaning all kinds of exterior surfaces and restoring them to like-new condition. Before you get started, we have some tips to help you get the most out of your efforts. We also have a list of some things that don’t stand up well to pressure washing.
If you don’t have a pressure washer and don’t want to buy one — don’t despair. They’re often available for rent at hardware stores or equipment rental stores. Just make sure you get a copy of the manufacturer guidelines or a thorough tutorial from the store before you begin.
Follow instructions. Review the manufacturer’s instructions before tackling the task at hand. Like most equipment, each brand and model has a few little nuances that make it unique. Even if you’re experienced with power washing, it’s important to learn how the one you’re going to be using works.
Protect yourself. Not only is the water coming out of the nozzle with great force, you’re often using cleaning solutions or chemicals to get the best results. Protect your skin by wearing gloves, closed-toe shoes, long sleeves and pants. Protect your eyes, too. Opt for full face protection if you want more coverage than goggles provide. Power washers generate a bit of noise, too. So ear protection is never a bad idea.
Protect outlying areas. Cover plants, vehicles, and anything else you don’t want to get hit or that could be damaged. If you’re not going to cover your plants and you’re using a chemical in your spray, give them a dose of water first. Dry leaves absorb more chemicals than wet ones, so a once over from the garden hose will offer some protection.
Pay attention to accessories. Always attach nozzles and other accessories before turning the power washer on. And watch the nozzle when it’s in use so it doesn’t come loose. Remember to pay attention to the direction you’re spraying and don’t point it at other people, animals or fragile surfaces.
Never leave the machine unattended. Like all power tools and equipment, leaving the unit unattended is not a good idea unless it’s powered off and put away.
Know when to get help. Call professionals for anything you want to clean that’s over one story and don’t tackle the roof. Professionals have the equipment needed to get up three or four stories without using a ladder. Roofs can be dangerous to work on and they’re easy to damage, without the right equipment you can do more harm than good.
Skip the spiders. Spider webs are nearly impossible to remove with a pressure washer. Go old-school with a broom or a dusting wand to remove those sticky webs before power washing.
Presoak with low-pressure. Presoaking the area with a low-pressure spray loosens the dirt. This can save you time and chemical cost.
Try it first. Try a small, inconspicuous area first to make sure the pressure level and cleaning solution doesn’t damage the surface.
Recommended materials. Use only the recommended detergents or chemicals for the item you’re power washing. Look for a product that is not only recommended by the power washer manufacturer, but one that is also approved for the surfaces you’re washing. For example, concrete driveways work best with a different solution than the siding of your house.
Go hot. Hot water works better at removing dirt than cold and it lets you use less cleaning solution. Much like washing dishes at home, the hot water does a great job of loosening up stuck on dirt.
Up and then down. Wash from the bottom to the top, then rinse from the top down. Work in sections so you can wash and then immediately rinse so the cleaning solution never has a chance to dry. Direct the water downward to force dirt down rather than wedging it into cracks and seams.
Water pressure. Commercial contractors typically use 4 to 6 gallons per minute (gpm) at 1500 to 3500 pounds per square inch (psi) for most tasks. Most home tasks can be accomplished with a little less force at 3 gpm and 3000 psi. Wood is a little different as it can be damaged by too much pressure. If you’re cleaning a wood structure, lean toward 500 to 2000 psi.
Nozzle selection. The nozzle you choose has two major considerations: the hole size and the spray angle. The two features determine gpm and psi. A larger nozzle means the psi is reduced but the flow remains the same. Spray angles range from 65 degrees to 25 degrees with a mid-point of 40 degrees a favorite among professionals. A smaller spray angle does have the ability to tackle stubborn dirt, but it also increases the possibility of damage and streaking.
Adjust the distance. For the best results, adjust the distance between the nozzle and surface. Moving closer not only gives you more pressure, but the water is hotter when it comes in contact with the surface. For less pressure and cooler water, move back.
Brick. Brick sidewalks and brick on your building can be pressure washed if you’re using the right cleaning products. Watch out for loose or chipped spots where the power washer could cause more damage. If there are any cracks in the mortar, repair them first and give them time to dry and cure before washing. Remember that the patina protects the brick, so be careful to wash away only the dirt and grime.
Concrete. Whether you have concrete sidewalks or driveways, you’ll love the results you get with pressure washing. Make sure you’re using the right detergents to get a great looking finish. Again, be careful of chips or cracks, since the pressure washer may cause them to expand or come loose. Stamped concrete can be power washed, but treat it with a sealer first to help protect it.
Cut stone. Some cut stone, like marble, looks great after power washing, while other types, like limestone, are a bit more fragile. The best approach for all cut stonework is to start with a lower pressure and then slowly move a little closer to get the results you want.
Siding. Whether your home has aluminum, wood or vinyl siding, it can be pressure washed. If the surface is painted, you might want to use less pressure so you don’t wash off the paint.
Decks and patios. If the surface is painted, remember to test an area or use a nozzle with less pressure first to make sure you’re not stripping off the paint or the finish.
Gutters and soffits. Check to ensure they’re firmly attached, and then spray away. If you’re trying to wash dirt out from behind gutters and soffits, remember there’s a building behind them. Take care to avoid forcing dirt and water up into the walls.
Wicker and metal outdoor furniture. These can usually tolerate power washing, as long as you use a lower pressure setting. You’ll want to test a small area first to make sure you’re not removing any paint or finish. If your wicker furniture is glued together, use cold water so you don’t soften the glue.
Boats and vehicles. As long as you’re pressure washing, you can clean your boat and car, too. But they do need special chemicals designed to work with their unique finishes.
Features of the house. While your siding will look good after pressure washing, you can do damage to other parts of your home. Be cautious around windows, frames, doors, overhangs, screens and any decorative elements on the exterior of your home.
Wooden outdoor furniture. Pressure washing wood has a tendency to damage it, which can ruin your outdoor furniture. Instead, try using soapy warm water and a scrub brush to get your wooden outdoor furniture back into shape.
Fabrics. Fabrics are not designed for power washing. Skip the pressure washer when it comes to cleaning patio umbrellas, cushions, pillows and awnings.
Grill. Pressure washing a grill can drive water, grease and dirt into burners, possibly affecting gas flow. It’s best to rely on elbow grease to spruce up your grill.
Pressure washing can be a quick and easy way to get your home and property looking like new again. The most important thing to remember is to use the equipment as recommended by the manufacturer — for safety and the best results. Starting slow and farther away will give you an idea of how effective the power wash will be. Then you can gauge how much closer you need to move to get the results you want without damaging your property. When you’re finished, stand back and admire your handiwork!