Can You Pressure-Wash Trex Decking?

When you want the look of a wood deck without the hassle of staining or painting it every couple of years, a composite material like Trex decking is a pretty attractive option. It's made of a combination of recycled plastic and sawdust, making it resistant to pests, rot, and decay. While it's definitely a much lower maintenance option than traditional wood, it still needs to be cleaned from time to time. 

If you were accustomed to whipping out your pressure washer for your old wood deck, you may wonder if you can do the same for a composite material such as Trex. The answer is: it depends. You can use a lower pressure setting with a fan attachment on Trex's Transcend, Enhance, and Select series decking. However, you should avoid the pressure washer altogether on the brand's earlier generation products.

According to Trex, "The use of a pressure washer on your deck surface could damage the decking surface and will void the warranty." When cleaning its products that can withstand a little more force, it's still a good idea to determine when to soft wash instead of pressure wash. In many instances, using a hose, some mild soap, and a soft-bristled scrub brush will get the job done, and you won't have to worry about potential damage (or the hassle of dragging the power washer out of the garage).

As long as you don't wait too long between cleanings, washing your Trex decking shouldn't be too hard. First, you'll want to know how to prep before power washing your deck. Move all furniture and plants out of the way and sweep your decking with a broom to remove any leaves, large chunks of dirt, or other debris. To clean pressure-wash-compatible Trex decking, use no greater than 3100 psi. Fill the soap dispenser, and then spray each board, holding the pressure washer's fan tip at least 8 inches above the surface. Rinse well afterward.

When choosing a soap for your pressure washer, go for something mild. You'll also want to avoid the cleaning agents you should never use on composite floor decking, which include bleach and acids. For earlier Trex lines, skip the pressure washer and use a garden hose, mild soap, and a soft-bristled scrub brush to clean your decking, rinsing thoroughly after cleaning. Cleaning regularly will help prevent mold and mildew from forming on the deck, but if you still see a few spots, scrubbing with soap and your scrub brush will remove them.