Whether you live in the thin air of Denver, CO, fight the smog in LA, deal with the salt air of Seattle, or enjoy the hills of Portland, your composite deck is going to need to be cleaned. Nothing in life is indestructible and, while it comes close, your composite decking is no different.

Your best answer to almost every cleaning situation will be soapy water and a soft-bristle brush followed by thorough rinsing. We stress the rinsing because you don’t want a film of dirty water drying onto your planks and maring their beauty.

For maintenance cleaning, we recommend a schedule of every six months. Spot cleaning and cleanups from spills should happen as soon as possible. While composite decks are resilient, they will still take on stains if spills are left to sit for too long. Your stain warranty will not cover stains from debris that sits for more than seven days.

Now Let’s Get Specific

For early-generation composite products (Trex Accents®, Trex Origins®, Trex Contours®, Trex Profiles® or Trex Brasilia®), we recommend a semi-annual cleaning with a composite deck cleaner. If your deck is one of the high-performance product lines from Trex [Trex page link here](Trex Transcend®, Trex Enhance® or Trex Select®), soap-and-water cleaning or a gentle pressure washing will do the trick.

Always defer to the cleaning instructions that came with your particular composite decking material. When it comes to the capabilities of composite materials, the manufacturer will always know best.


Spray away any debris with a simple garden hose, then use warm, soapy water and a soft-bristle brush to remove dirt and debris from the embossing pattern.


Most colored chalks are permanent and may discolor the surface. Use only Irwin Strait-Line®* Dust-Off Marking Chalk (purple) available at www.Irwin.com.


Use a garden hose or a broom to remove any debris from the area of concern. Once the deck surface is dry, apply a “brightener” ** to the deck as directed by the manufacturer. Deck brighteners contain oxalic acid, which will remove tannins.


Only use a plastic-bladed shovel to remove snow from the deck as a metal blade will score the planking and damage the protective coating. Use calcium chloride or rock salt to melt the snow and ice from the deck surface.


You should remove all food spills as soon as possible. Be sure to clean the surface within seven days of any spill to preserve your stain warranty. To remove spills, spray your deck off with a hose, and then use warm, soapy water and a soft-bristle brush to remove the spill from the embossing pattern.


If debris, such as pollen and dirt, is allowed to remain on the deck surface, mold can feed on the biofilm. Use a hose and warm, soapy water with a soft bristle brush to remove the food source and any mold that may have started growing on your deck.


A pressure washer with a fan attachment. Make sure that the pressure is set below 3100 psi (going over 3100 psi can void your warranty and damage the planks). You may use a soap dispenser as well. Following these steps will give you the best results without damaging your planks:

  1. Spray your deck with soap.
  2. Gently scrub each deck board with a soft bristle brush.
  3. Spray/rinse each deck board while keeping the fan tip at least 8″ from the decking surface.
  4. RINSE THOROUGHLY (If dirty water from your cleaning activity is left to dry, it will leave a film on the decking surface).


NEVER use acetone or other solvents on Trex Transcend and Select railing. Doing so will damage the beauty of the surface.

For color transfer issues use Mr. Clean®, Magic Eraser® Original or Magic Eraser® Extra Power to help remove this.****

For small surface scratches, marks or scuffs, use Dupli-Color Scratch Seal™ Clear Sealer Pen.*****

If you ever have any questions about how to care for your composite deck in either the Denver, LA, Portland or Seattle area feel free to contact us at Custom Decks. We’ll be more than happy to go over the proper care for your type of deck.


* Strait-Line® is a registered trademark of Irwin Industrial Tool Company.

** Use of products containing bleach or acid will lighten the surface of Trex. Use in an inconspicuous area to determine whether you like the effect. Neither product will affect the structural integrity of Trex.

*** Use of a pressure washer greater than 3100 psi could damage the boards and void the warranty.

**** Mr. Clean® and Magic Eraser® are registered trademarks of The Procter & Gamble Company.

***** Scratch Seal™ Clear Sealer Pen is a registered trademark of Dupli-Color® Products Company.

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