Home> Wood and Deck Restoration> Composite Deck Maintenance




trex_moldIn the past 15 years there has been a substantial amount of composite decking products to hit the market. Some of the more popular are Trex, Azek, and TimberTech. Composite decking is a mixture of recycled plastic and wood fibers. They were designed initially to be maintenance free with no need for cleaning and or an application of a sealer/wood stain.

The industry has since changed from "maintenance free" to" "low maintenance" due to the many issues with mold and mildew. There have been class action lawsuits from this but the fact remains that there is no such thing as "maintenance free" when it comes to horizontal exterior surfaces. It does not matter what the substrate is, all will need periodic cleaning and or sealer.

The question is how should I maintain my Trex or Composite Deck so that it looks good continuously? Well it is an fairly easy process and should be done whenever the mold/mildew becomes noticeable. Failure to clean ASAP could result in the mold spores never coming clean!

We do not suggest bleach for cleaning composite wood. While it does help remove the mold and mildew, it can lighten the wood fibers of the wood in the decking, bleaching out the color. It is best to use a composite deck cleaner that contains sodium percarbonate as the main ingredient. Sodium Percarbonate is registered by the EPA as a mold and mildew remover. It is a very effective chemical and is essentially harmless when it comes in contact with humans and vegetation.

  1. Clean off decking and remove all furniture 20+ feet away from decking.
  2. Use either the Defy Wood Cleaner or the Restore-A-Deck products. Both contain sodium percarbonate and additional surfactants that aid the process of cleaning exterior wood and decking. Both are powdered concentrates.
  3. Mix cleaner in a bucket with water. Warm water if possible will work better. Follow the directions as to how much cleaner you should add per gallon of water.
  4. Apply the cleaner with a pump sprayer or scrub bush. We suggest doing sections of 100-200 square feet at a time.
  5. Using a scrub brush or pressure washer, lightly wash off cleaner, dirt, grime, mold, mildew, and algae. Repeat if needed.
  6. When done thoroughly rinse all decking, house and vegetation.
  7. Optional: Application of a clear water repellent will minimize the mold growth. It is a very easy step. We suggest the SuperSeal-M Water Repellent. It applies with pump sprayer and will not change the appearance at all once dried.
*Update: Another popular option for protection is the Defy Extreme Clear. This product offers even better protection as it contains "zinc oxide". Zinc oxide combats the growth of mold and mildew. In addtion the Defy Extreme Clear will "enhance" the color of the composite wood just slightly, restoring some color back into faded composite wood decking.


Keeping up with the cleaning of your composite deck is essential! It will keep the wood looking better and is healthier choice for people who have allergies.

If you have any questions please use the form below.

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Yes you would want the Defy Composite Sealer for this. It is an improved version of the Extreme, formulated for composite wood.
TheSealerStore , August 31, 2015
Thanks for your article on Composite Deck Maintenance. Question… Saw your recommendation to use Defy Extreme Clear on a composite deck. When I go to research the product it does not seem that Defy recommends it for composite. It just talks about wood. Can it be used on composite. I’m looking to enhance the color of my composite deck where it has faded. Would there DEFY Composite Deck Waterproofing Sealer do the same thing.
Scott Diehl , August 31, 2015
re: The name of the stain dropped on our deck
Sorry but no idea as to how to remove this. I would contact Behr for some help.
opwdecks , August 12, 2015
The name of the stain dropped on our deck
The stain is Behr Premium wood coatings. Semi transparent weather proofing all-in-one wood stain and sealer. Tint base 5077. Any suggestions appreciated.
Kara R. , August 11, 2015
re: Wood stain drips
Depends on the stain brand and type of stain that it is. Maybe a deck stain stripper but it is iffy.
TheSealerStore , August 11, 2015
Wood stain drips
A contractor was staining the wooden pergola that is over our deck and dripped the dark brown wood stain all over it. Is there anything that will remove these drips?
Kara R. , August 11, 2015
I am sorry but we do not sell anything that will help in this scenario. I would contact the manufacturer of the Trex for some help.
TheSealerStore , May 04, 2015
Hello, wondering if you can please help. I powerwashed my porch yesterday to include the composite wood floor (believe is trex boards). Well while I was powerwashing I noticed I had the typical black and green mold spots but they would only come off if I put the nozzle pretty close to the floor. Well by doing that, I believe I took off the finish of the boards. The fllor looked amazing while it was wet and being powerewashed but this morning I went out to look at it and now that it is dry... seems like colors are faded, small white dots all over the place, and the shiny luster is gone. Can you please let me know what I can do to fix or improve the look??? Will Penofin Knotwood penetrating oil finish help? and Penofin Color enhancer? Please help I am so disappointed
Brian C. , May 04, 2015
re: Azek Decking
Thomas, we have sealers that help prevent mold but no coating will restore the lost color or finish that the Axek originally had.
TheSealerStore , November 13, 2014
Azek Decking
Hello Sir,MaMa,
I have a Azek deck and I need something to clean it real clean and I would like to restore it back to it color, now it has a white sheen on it and it look duel no shine. I have used Deck Max it lasted 3 month and know it gone.
I clean the Deck with there cleaner and install Deck Max revitalize on my deck just like the internet said by Deck Max.
Sir,MaMa, will you please help me to get the Deck looking like it should.
Thank You Thomas Baker
Thomas Baker , November 12, 2014
re: Defy Extreme
Defy Extreme or the Defy Composite Sealer will not enhance the color as if wet with water or darken the appearance. They will not remove stains either. We do not have anything that will darken the TREX.
TheSealerStore , August 29, 2013
Defy Extreme
My brown trex is on a screened in porch so the fading has not been horrible. However, it no longer has a darker look or luster and there are a few grease spots which did not come out when I cleaned the porch using soap, a brush, and power washer. The porch did look great while it was still wet, but dryed a dull brown and teh grease spots were still visible. It appears you're recommending Defy Extreme as a solid option for future protection. The porch has never been protected. Will Defy also help with removing the stains and will it provide the benefits of a darker look? If not, do I need to take a few steps with various products? Also, if it does, will I have any issues with flaking in the future (e.g. is it like a poly or paint). Thanks, Douglas
douglas , August 29, 2013
Leaning on the trex rail makes people's arms itch. Feels like an "insulstion " itch. How do I seal it to stop that feeling
Diane Honigford , May 21, 2013
I have. Tre x d elks get a lot of sun and h a ve faded considerably how. Can I restore th e look so it looks better?
Spent a lot of money and looks terrible thank you
Fran garigiulo , May 21, 2013
re: composite deck and some olive oil was dripped on it.
Sorry but that is not possible to fix.
TheSealerStore , December 17, 2012
We have a 6 month old composite deck and some olive oil was dripped on it. I used an on line "home remedy" of baking soda and vinegar to remove the spots but it also faded the color of the decking where I applied the mixture. Help! Is there something I can use to restore or brighten these lighter areas? I just feel awful that I made a bad situation even worse with this "home remedy". Thank you.
BJ , December 14, 2012
re: Veranda composite restoration
Hard to say. You cannot fix the discoloration from UV fading. What are the stains exactly? Grease, oil, dirt, grime, etc.
TheSealerStore , July 21, 2012
Veranda composit restoration
In addition to mold stain we have discoloration where furniture has been moved, and other stains from heavy use. It is exposed to direct sun and weather. We just cleaned with "Expert Chemical's Composite Deck Cleaner and Enhancer" but the discoloration is still there and some stains. Your suggestions?

PS:wish I had found your product first.smilies/sad.gif
Larry Scott , July 20, 2012
re: shoveling snow off deck
I am sure you are fine with both.
TheSealerStore , May 16, 2012
we live in Michigan an my husband insist on shoveling snow off deck is this doing any harm also can you use charcoal when grilling on deck
Towns LT , May 16, 2012
re: Composite Deck care
You cannot add a clear coat on top of Messmers Composite deck Finish. You could try the Defy Extreme Stain in one of the three tints. It will add color and have the zinc oxide as well. It should absorb into the composite wood just fine. I would only apply one coat.
TheSealerStore , April 04, 2012
Composite Deck care
I have a question about restoring my Trex composite deck. I want to clean the mildew off and apply Messmer's Composite Finish to restore color. Can I then add a coat of the clear zinc finish to "seal it" and prevent mold/mildew from recurring?

Tom , April 03, 2012
re: Homeowner
You can add a penetrating stain to Trex. Any of these will work.

TWP Stains
Armstrong Clark
Defy Extreme
Messmers UV Plus
Penofin Stains
TheSealerStore , March 19, 2012
My TREX deck has faded from sun and cleaning. Has anyone had success with a penetrating stain to restore color?
Matt Taylor , March 19, 2012
re: Ooops
I would try a deck stain stripper.
TheSealerStore , October 04, 2011
Hi -

I dripped Messmer deck stain on my composite decking. Is there a way to remove the drips?

Rhonda Huseby , October 03, 2011
I agree in industry maintenance free to low maintenance is big issue due to compitation.I just wanna thank you for sharing your information and your site. I’ve learned new about composite decking today. Thanks
Composite Decking , June 20, 2011
re: cleaning a deck that has been stained
Pressure washing alone does not remove solid stains. Is the stain transparent or a solid color?
TheSealerStore , May 23, 2011
cleaning a deck that has been stained
I just bought this house last Aug. and did not get time to clean the dirt and shingle debre ,mess from the new shingles that the previous owner had replaced. I tried using a course hand brush and water on one board and it came off. However this is a large deck and I do not want to clean the whole deck on my hands and knees. The deck has yellow stain on it that the previous owner had applied on recently. Can you advise me on an easier way to get my deck cleaned? Would a pressure washers take the stain off? Thank you Linda
Linda kaczmar , May 23, 2011
Composite decking has become a real hot topic in the industry over the past few years and your advice is "dead-on"...especially with the importance of utilizing an oxygenated bleach cleaner.

The only popint that I would add is that sealing composite decking, after cleaning, with a clear sealer containing zinc nano-particles, such as Defy Extreme Wood Finish - Crystal Clear, will go a long way in delaying the return of the mildew growth. Zinc has been used in various forms and applications to combat mildew and algea growth and the zinc material in the Defy Extreme nano formula has been tested to perform exceptionally well in that application.
Dave Barnes , May 15, 2011
re: comments from users trying the SuperSeal-M Water Repellent
We personally use it and have customers who can keep the mold off annually or even for 2 years.

Another option is the Defy Extreme Clear. It contains "zinc oxide" which is a known mold killer. Works very well.
TheSealerStore , May 15, 2011
I need to pressure wash composite deck 3 times a year to remove black mold spots. It comes off rather easy without the need for any cleaning products such as sodium percarbonate cleaners. However, I am interested in any comments from users trying the SuperSeal-M Water Repellent to see if will reduce the frequency of deck washings.
Doug Chapman , May 14, 2011



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