Regular cleaning is crucial if you want your composite decking to stay in good condition. However, you need to cleat in the right way so you do not cause damage to the surface. Many people are unsure whether it is safe to use a pressure washer on composite decking and if it can cause damage.
Pressure washers are safe to use on composite decking but they can damage the surface when used incorrectly. The PSI must be kept between 1500 and 3100 to avoid scratching. However, it is always best to refer to the manufacturer’s guidelines to be safe as different materials vary.
If you are going to clean your decking with a pressure washer, read this guide first to learn more about the correct way to do it.
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Can Pressure Washing Composite Decking Cause Damage?
Pressure washers are very effective at cleaning but using them incorrectly can cause damage. The high water pressure from a pressure washer can be enough to permanently damage your composite decking but the chance of this happening is small if you use it correctly. Here are some tips for using a pressure washer on composite decking:
- Direct the nozzle toward the gaps between boards, not the surface of the boards
- Start with a low-pressure setting and gradually increase until you achieve a good level of cleanliness
- Apply a gentle amount of downward force as you spray
- Keep constant steady strokes over each area instead of short bursts
It is also important that you use the right PSI setting on your pressure washer to avoid damage. When the PSI is set too high, it can scratch the surface.
What PSI Can You Use on Your Composite Decking?
PSI (pounds per square inch) is used to measure the amount of force that a pressure washer produces. For example, if the PSI is 1000, that means that the pressure washer will apply 1000 pounds of force per square inch on the surface being cleaned.
The ideal PSI for composite decking varies depending on the type of deck, so you should always follow the advice of the manufacturer. However, as a general rule, you should use somewhere between 1500 and 3100 PSI. Exceeding 3100 PSI is likely to cause lasting damage to your deck.
How Not to Pressure Wash Your Composite Decking
There are a few common mistakes people make when pressure washing their decking. Firstly, using the wrong PSI will cause scratches and can strip the top layer of stain from the wood.
The distance between the end of the nozzle and the deck is important too. The nozzle should be kept about 8 inches away from the surface to avoid damaging it.
Finally, you need to be aware of the pressure washing technique. The water needs to hit the deck boards evenly and gently so that the fibers are not disturbed too much. Using short bursts of high pressure can damage your decking just as much as using a low PSI for longer periods.
You should only use a downward motion with your cleaning tool when pressure washing composite decking to prevent damage. Pressure washers that have rotating jets are almost always best avoided because they can cause significant scratches unless used very carefully indeed.
Can a Pressure Washer Wash Away Mold and Mildew from Composite Decking?
Yes, you can use a pressure washer to clean away mold and mildew. However, it will only strip superficial stains from the surface. It is much more effective to use a specially formulated composite deck cleaner that is designed to remove mold and mildew. You can apply the deck cleaner and scrub it to clean off all of the stains before rinsing it clean with a pressure washer. Check out our article on the best composite decking cleaners to make sure that you are using the right product.
What if you Splinter Up or Damage Your Composite Decking?
Composite decking is durable compared to other types of wood but it can still be damaged. If you splinter up your decking, you can attempt to make repairs yourself. Wax sticks can be used to cover small, superficial scratches. Mixing composite deck shavings with some wood filler can help you fill in larger cracks and chips too.
You can also buy composite decking repair kits like the NewTechWood DeScratch Composite Decking Repair Kit. These are great for removing scratches and restoring the color on damaged areas. However, if the damage is extensive, you may need to replace the entire board.
Pressure washers can be useful for cleaning your composite decking, but it’s crucial that you follow these guidelines to avoid damaging your decking.
Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.