Can You Power Wash A Composite Deck?

Composite decking is known for how easy it is to maintain. There is no need to stain it, replace rotted boards, or deal with the other hassles that come with traditional wood decks. 

The accumulation of dirt, mold, moss, barbeque stains, algae, dust, and other mineral deposits is a common occurrence on composite decks. While maintenance is minimal, there is no doubt that it will need to be cleaned on occasion.

Most people recognize that one of the easiest ways to clean a deck is by using a power washer. However, the big question is “can you power wash a composite deck?”.

Power Washing a Composite Deck

Every spring for several years I filled a bucket with water, added a bit of Dawn dish soap, and sponge cleaned my composite deck. My deck came out looking close to new new every time. The problem was that this cleaning process ate up a good portion of my weekend as I labored away. 

I then wised up and borrowed this Simpson Pressure Washer from a family member to see how well it would work on my composite deck. I checked with Trex, the manufacturer of my composite decking, to verify if a pressure washer was suitable to use for cleaning purposes before I started. 

I found out that the ability to power wash a Trex deck depends on the type of decking used. For example older models of Trex decking cannot be power washed whereas newer high-performance decking can be power washed. 

Since each manufacturer has different recommendations on power washing their decking, we have provided a summary (see below) of what popular composite decking manufacturers state about power/pressure washing their decking. Click the links provided for additional details before power washing. 

Cali Bamboo – They recommend having a professional power wash Cali Bamboo decking at a low pressure with a wide fan-tip. Power washing damage can lead to a loss in the warranty. 

CertainTeed – A pressure washer can be used at 1,500 psi or less with a wide fan-tip at 12 inches or above. Do not pressure wash when mold or mildew are on the surface. They advise to use a skilled professional to complete the pressure washing. 

DuraLife – They recommend against using a pressure washer on their decking. 

Envision – You can use a pressure washer at 1,000 psi or less with a fan-tip to remove mold and mildew. 

Fiberon – This type of decking can be pressure washed at a foot distance or more with a wide fan-tip nozzle while moving in the direction of the grain. A 2,500 psi maximum is recommend. The manufacturer states that a pressure washer should not be used when mold or mildew are on the surface. 

Lumberock – A maximum of 1,800 psi is recommended with a 20-degree nozzle. 

TimberTech Azek, TiberTech Pro, TimberTech Edge, Reliaboard, Docksider – The company states that power washing should be used for rinsing only with a maximum pressure of 1,500 psi. A fan-tip should be used – working with the grain while spraying the decking. 

Trex – Trex advises against power washing their older generation decking. This includes Accents, Origins, Brasillia, Profiles, or Contours. You can power wash Transcend, Enhance, or Select. A maximum of 3,100 psi, a fan tip, and a spray no closer than 8 inches is recommended to avoid damage.

Unknown Composite Decking – If you are not sure what type of composite decking you have, proceed with caution. The best route to take is to hand wash it annually or semi-annually. If you opt to power or pressure wash the decking, you should start using a low psi, at 12 inches or more,  with a wide fan-tip in an  inconspicuous area.  


Please contact the manufacturer or read the literature that came with your decking if you have any doubts on power washing. A power washer can create serious damage to a composite deck if the pressure is too high, an inappropriate nozzle is used,  and/or the nozzle is held too close to the surface. Always start in an inconspicuous area when power washing to test that it is not damaging the decking.  The safest course will always be to hand wash your composite decking. 

Top Feature Image Credit: Fiberon