Stains on concrete are not only unappealing, but can also weaken the surface of your driveway. For outdoor cleaning, a pressure washer is fast and efficient.
Pressure washers are portable and can run on either electricity or gas. The engine powers a water pump, which is fed by a garden hose. The unit pressurizes the water so it comes out with greater force than a garden hose alone could muster.
This guide will show you how to pressure wash your driveway. It also includes information about how to get your driveway ready to pressure wash, as well as safety tips.
Prepare the Area
Clear loose material, like stone, dirt and other debris, off the driveway surface. You can use a leaf blower or a broom.
Make sure that there aren't any toys or bikes in the driveway. Move potted plants and outdoor furniture out of the area you'll be pressure washing.
If your driveway abuts any walls or doors, you may want to cover them with a tarp and some painter’s tape. Covering walls and doors will protect the finish from accidents or flying debris.
If there are in-ground plants close to your driveway, consider putting a tarp over them as well. Plants can be damaged by the detergent used during pressure washing. However, don’t keep your plants covered for long, because a tarp can limit their air supply.
Take a few moments to determine which end of your drive is the highest and what direction water flows when it runs across the surface. You should start pressure washing at the highest point so that the water will follow the path of gravity. It should flow away from your work area.
Degrease the Surface
Applying a degreaser will loosen stains in the concrete, allowing you to pressure wash them away. Some pressure washers have an attachment tool for applying degreaser. Otherwise, scrub the degreaser into the concrete with a stiff-bristled brush or push broom.
Get the Pressure Washer Ready
Before you begin pressure washing, read the instruction manual. Follow the directions that are specific to the model you’re using.
Generally speaking, you’ll need to connect the spray wand to the washer using a pressure hose, and the washer to a water supply using a garden hose. Different nozzles are available for different purposes. For applying the detergent, use the low-pressure nozzle. For rinsing, use a high-pressure nozzle.
Do not use the high-pressure nozzle on brick surfaces. A pressure washer can even damage concrete, so test it out on a less visible spot before you start working on the entire driveway.
The cleaning power of a pressure washer is determined by combining its water pressure (measured in pounds per square inch, or PSI) with the amount of water used to clean a surface (measured by gallons per minute, or GPM). To calculate its cleaning power, or CP, multiply a pressure washer’s maximum PSI rating by its GPM flow (CP = PSI x GPM).
A pressure washer is designed to strip substances away from surfaces, so be careful when using one. Wear safety equipment to protect your eyes and ears, as well as closed-toe shoes or boots, while using a pressure washer.
Being hit with water from a pressure washer can cause severe injuries. Don’t point the pressure washer’s spray wand at other people. Keep completely out of the path of the spray as you work. You don’t want to try rinsing your hands with a pressure washer, for example. If the pressure washer spray does come into contact with your body, have the injury checked out by a medical professional as quickly as possible.
While you’re pressure washing, stay aware of what’s around you. Don’t back up into the road. Keep an eye out for kids or pets that might wander into your area.
Clean the Concrete
Start at the higher end of the drive and work your way down it in the direction of water flow.
- Point the spray wand at the driveway surface and press the the trigger.
- Sweep the nozzle steadily back and forth across the concrete, overlapping each stroke by several inches.
- Once you’ve applied detergent to the entire surface, let it stand for 15 minutes or so. You may need to rewet it occasionally to make sure that it doesn’t dry out.
Rinse the Concrete
After 15 minutes, switch to a high-pressure nozzle. Set the pressure washer to its rinse mode.
- Repeat the sweeping pattern you used before, washing away the detergent and using the spray to lift any grime or stains you find.
- Make tighter sweeps to lift heavier stains. Be sure to rinse away all of the detergent.
- Allow the driveway to dry.
Seal the Concrete
After the concrete has dried completely, apply a sealant to help ward off future stains. Using a roller with an extension poll, coat the driveway surface with a concrete sealant. Allow the surface to set a full day before using the driveway.
Once you know how to pressure wash your driveway, you can improve its appearance and even increase the curb appeal of your entire property. You’ll want to use caution as you pressure wash, however, because the spray can damage the surrounding area.
If you want to try using a pressure washer, but aren’t ready to invest in your own, The Home Depot offers tool rental. You can rent a pressure washer and accessories, like a driveway and surface cleaner, that are perfect for your project.