Is it a Good Idea to Use A Power Washer on a Wood Deck?

This question confronts every homeowner with a beautiful deck they would like to maintain in perfect conditions. After obliterating the gunk, grime and debris from your driveway or pool area with your spiffy power washer, it is only natural to wonder if you can perform the same in-depth cleaning on other exterior elements of your home.

Decks can succumb to an accumulation of all kinds of dirt, scum and grime and it would seem the easier solution will be to apply pressurized water to the problem and be done with. But, is this actually the best way to deal with the problem? Here is what you need to know about washing your deck with a power washer.

Potential Damage Caused by Power Washing Your Deck

Unlike the concrete on your driveway, or even the vinyl siding on your home, decks are typically made of wood. Wood is not nearly as strong and resistant to water as concrete or vinyl. As a matter of fact, your pressure washer could make an area of small damage or wear far worse. The high pressurized water can split the wooden fibers apart and cause serious damage that will take costly repair work to correct.

It is not just wood that can be damaged by the high pressure of a power washer either. If your deck contains PVC elements, you will find that these can also become affected by the powerful stream of water

Many wooden decks are also made of composite materials, which are basically plasticized wood which can be sturdy building materials. Unfortunately, these are also highly susceptible to the high power of a pressure washer. Even worse, you will have to pay for your damage yourself as this is not a type of damage that is not covered by composite deck warranties

When Is Power Washing My Deck Okay?

On the other hand, there are some situations where a pressure washing for your home’s deck may be just fine. But, you will have to keep the points mentioned above in mind while handling this particularly damaging task.

Here are some important pointers to follow when power washing your wooden deck.

  1. Get the Right Pressure

You will want to use a lower pressure on your delicate decking materials. If you have a deck made of softer woods, like cedar or pine, you will want to use a lower pressure setting. Softer woods should never be impacted by pressures that exceed 600psi and 500 psi would be a better choice to be safe. You may go as high as 1200 psi on hardwood, but looking for the lowest effective psi setting is highly recommended.

  1. Use the Right Tip

The best option for preserving your wooden deck is a 45° spread tip. Some seasoned professionals recommend the rotating tip, but this should be used carefully.

  1. Test a Small Portion

If your deck is older or you just want to play it safe, the best way to begin will be by testing the pressure from your washer on a small portion of the deck that is somewhat inconspicuous. A stair will be a lot easier to replace then one of the actual deck boards in case of serious damage. Begin with a very low setting and work your way upwards pausing between strokes to examine the effects on the wood.

  1. Get to Work!

If you feel you have found a pressure that will not damage your wood, you can proceed with caution. Remember that different areas of the deck may be more susceptible to damage and work carefully.

  • Keep the nozzle 12”to 24” from the wooden deck surface you are cleaning.
  • Use a sweeping motion to gently lift the scum and debris. Keeping your arm straight as you do will ensure an even amount of pressure.
  • Work in the same direction as the grain of the wood.

Should I Replace or Repair My Wooden Deck?

Replacing a wooden deck can be costly, which is why you won’t want to opt for a full-scale replacement unless it’s absolutely necessary. With that said, if your deck is in very poor condition, repairs may not be a viable option. Watch out for these warning signs so that you know when your wooden deck needs to be replaced.

The Wood is Rotting

If the wood on your deck is beginning to rot, it’s likely that repairs won’t be sufficient. Rotted wood can have a negative impact on the appearance of your deck, and it can also be a serious safety hazard.

Wood rot spreads over time, which means that even a small amount of rot could indicate that you need to take action. While repairs may be sufficient if you catch the issue early, you’ll want to use a sealant so that you don’t have problems with rot going forward.

Railings are Loose

A loose railing is an issue that will need to be addressed as soon as possible. If someone leans against a railing that is loosened, they could be seriously injured or worse. It’s possible to replace loose railings, but if this is a wide-spread problem, you may find that it’s a better choice to replace your deck.

You need to make sure that you are able to use your deck safely. Having secure railings is a part of that. The structure of a deck can weaken as it ages, and in some cases, this will lead to a deck needing to be replaced.

You Have Issues With Mold or Mildew

Mold is dangerous to have in the home, but it can be a threat when it’s in your outdoor living space as well. Mildew can be another serious problem. It’s important to remember that mold isn’t always readily visible. Even if you address the mold you can see, there may be more mold beneath your deck.

Replacement isn’t always necessary if your deck has an issue with mold, but it is something you’ll want to consider. You should be particularly wary if you see fungal growths that resemble mushrooms.

Your Fixtures are Rusted

If the fixtures and fittings that hold your deck in place have begun to rust, your deck may not be secure for much longer. It’s smart to examine fittings from time to time and make sure that they are in good condition.

Broken or rusted fittings and fixtures can and should be replaced. However, if this is a chronic issue for you, it’s a sign that your deck has reached the end of its lifespan. In a scenario like this, you may be better off completely replacing the deck before a major issue occurs.

Other Signs of Significant Damage

In addition to the problems listed above, you’ll want to keep a watchful eye out for other signs of severe damage. If your deck has cracks, holes, broken boards, or other serious problems, you’ll want to take action. Termites are another thing you’ll want to watch out for.

Repairing the damage is easier if you catch these problems early on, which is why you’ll want to inspect your deck periodically. Compare the cost of regular repairs to replacement. In some situations, you may find that it’s more cost-effective to replace your deck entirely.

It can be difficult to determine whether you should replace or repair your wood deck. The best course of action will vary based on a number of factors. Keep this advice in mind. No matter what you choose to do, you’ll want to make sure you work to protect your deck against damage in the future.