Should You Regularly Use a Power Washer on a Wood Deck or Composite Deck?

Are you overwhelmed by the dirt and grime that accumulate on your deck? Has a mysterious gunk on the deck’s surface started to ruin your outdoor space’s once-beautiful appearance? You might be tempted to resolve the issue by taking a power washer to your deck and aggressively spraying it down. If that's you, put down the sprayer and walk away. Power washers can actually do more harm than good for most deck materials.

Potential Damage Caused by Power Washing Your Deck

Wood decks are especially vulnerable to power washing. The pressure exerted by the power washer can easily lead to splintering. If any area on the wood deck is already beginning to split apart, power washing can cause that split area to expand.

Wood, however, isn’t the only decking material that can be permanently damaged by power washing. Softer materials, such as PVC, can essentially be engraved by a power washer if the pressure is set too high.

It’s also a bad idea to use a power washer on a composite deck. The power washer can actually take chips out of the composite material. To make matters even worse, damage caused by power washing is not typically covered in the warranties for composite decks. So, if you do damage your deck beyond repair, you’ll be paying out of pocket to fix it.

When Is Power Washing OK?

There are a few situations where it might be OK to use a power washer on your deck.

Decks made of ASA, which is essentially a high-end capstock decking material, tend to be a little more forgiving when power washed.

Wood and composite decks can also sometimes be cleaned with a power washer but only if you have a professional doing it.

When choosing a professional to power wash your deck, here are a few tips:

• Look at experience. Don’t just choose someone from your local power washing company. Choose someone who specifically has experience power washing decks.
• Low pressure is your friend. The professional should use a relatively low pressure setting (probably no more than 1,500 PSI) and a wide fan.
• Distance matters. The power washer should be held at least two feet off the ground.
• Don't overdo it. Don't have a professional power wash your deck too frequently. Once a year is usually sufficient.

Cleaning Your Deck without a Power Washer

The key to keeping your deck in great condition for years is to stay on top of the cleaning. If you haven’t already made washing your deck a part of your regular household cleaning routine, it’s time to start. At a minimum, set a goal to clean your deck every two weeks.

Fortunately, basic deck cleaning isn’t too complicated. The only materials you’ll need are:

• Broom
• Hose
• Bristle brush
• Biodegradable cleaning solution. Note: dish soap should work fine on your deck. Other homeowners use a mixture of powdered laundry detergent (without bleach) and water.

Here's a step-by-step breakdown of that process:

• Step 1. Start by clearing any outdoor furniture and other accessories out of the way.
• Step 2. Sweep any debris off your deck. If leaves frequently fall on your deck, you might need to sweep it off more frequently. When leaves get wet, they can leave a hard-to-clean residue on the deck’s surface.
• Step 3. Once you have swept your deck, test your cleaning solution on a small, inconspicuous patch of your deck first. This ensures the solution you're using doesn’t leave a stain.
• Step 4. Begin cleaning the deck using water, your cleaning solution, and a bristle brush. Once you start scrubbing the entire deck, you’ll need to apply some elbow grease. But don’t scrub so hard you scratch or splinter your decking material.
• Step 5. After scrubbing your deck, rinse it off with your hose.
• Step 6. Let it dry.
• Step 7. Move furniture and other items back.

Questions or Concerns about Your Deck Maintenance?

Wondering how to keep your deck looking great? Ready to replace a deck that's beyond repair? Design Builders would love to hear from you! Just drop us a line!