trex moldHow To Seal Composite Decking and Tips

Composite decking is a synthetic blend of recycled plastic and wood. In the past decade or so composite decking has really taken off. This popularity was mainly due to the term "maintenance free" coined by the industry. Some of the major composite decking companies like Trex, Timber Tech, and Azek claimed that the composite decking material did not need to be cleaned or sealed like wood decking.

Over the years many of the composite decking companies found themselves in class action lawsuits with deck owners because the composite material was prone to water damage, fading, and mild/mildew and in fact did need to be maintained. Since then the industry has changed the term to "low maintenance." The bottom line is there is no horizontal exterior surface that does not need to be cleaned and/or sealed on a regular basis to enhance appearance and maintain longevity.

When mold and mildew starts to become noticeable on your composite deck it is important to clean it properly. The sooner you clean it the better because if the spores stay embedded for long enough they can be nearly impossible to completely remove. Clean the composite material deck with a percarbonate wood cleaner to remove all the unwanted soils.

After cleaning a composite deck, applying a clear water repellent can help to minimize the growth of new contaminants. Some of the best sealers for composite decking contain "zinc oxide" which naturally fights against mold and mildew. See Defy Composite Deck Water Proof Sealer

Sealing a composite deck will also help restore color and aid in the cleaning process the next time the composite wood decking needs maintenance. Most of the composite decking sealers apply easily with a pump sprayer and are user friendly.

Composite decking maintenance is crucial to the appearance and life of the decking. Regularly cleaning and sealing a composite wood deck will give your family a safe and clean outdoor area and will ensure many years of use.

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    MICHEAL ROBERTS · 09/13/2023
    I HAD FADED COMPOSIT DECK A JUST PAINTED WITH SHERMAN WILLIAMS STAIN, CAN I SEAL IT AT THIS TIME BEFORE IT GETS DIRTY? how long should i wait bebore i seal ? just painted 3 days ago!
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    Paul · 07/14/2021
    I need to seal the edges of my new Trex Transcend decking as it is rounded and I cannot put edging on it.  Can I add stain to the  Sealant to match the color? Do I have to wait any period of time prior to doing so?
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      The Sealer Store · 07/15/2021
      No, you cannot do this nor can you seal/stain Trex Transcend as it is 100% plastic.
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    Joe · 11/14/2020
    I have recently had a Trex deck installed at my home. My concern is that I have a lot of puddled water on my deck when it rains. I have read somewhere that this is not normal. I’m worried that over time the deck will start absorbing that water and start causing issues like mold or warping. Will the Defy composite deck sealer/ waterproofing help with this? Thanks Joe
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      The Sealer Store · 11/15/2020
      If the Trex is composite and not 100% plastic it will help.
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    Vickey herron · 07/09/2020
    We have trex decking and some pieces are flaking apart. Can't afford new. Need to fix. What can we do
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      The Sealer Store · 07/10/2020
      It is not possible to fix this.
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    Bob M · 04/05/2020
    We have wood fiber/plastic composite deck @ 4 years old. we used a power washer to do a deep, much overdue cleaning. we noticed, after about 1/2 of the job done that fibers were being removed. the result has a rougher appearance than the original finish. Is there a product that can save the deck? it is made by AERT sold at Lowe's (maybe no longer). the deck is on the north side of the house so it is prone to mildew as well.

    thanks,
    Bob
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    Eric · 02/15/2020
    Can you use this when building a composite deck to cover the cut ends?
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    Fred Albert · 09/23/2019
    What is a good product to use to seal the cut ends of composite decking?
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    John Williams · 02/16/2019
    I want to use Trex to form hollow box/benches having sides which are perpendicular to my Trex deck. Is there a product to fill the gap between the Trex planks which form the sides of the banch/boxes?
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      Rene · 03/28/2019
      Can i stain my trex decks
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        The Sealer Store · 03/28/2019
        We do not sell any stains that work with composite wood like Trex.
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      The Sealer Store · 02/17/2019
      Not that we know of.
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    John · 09/13/2018
    Would an oil based clear sealer work on a 1st generation Trex deck? I have power washed it for years so it is clean but would like to protect it from mold and mildew further. Do you sell oil based or only synthetics and which would work best?
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      The Sealer Store · 09/13/2018
      No, a clear oil-based sealer will not work. Best to use the Defy Composite sealer.
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    Debby · 07/16/2018
    My trex decking is 4 yrs old. It is trex select. It is under a covered patio. The colors are saddle brown with burgundy edges(can’t remember what they called the color ) my problem is it gets very dirty, because of our dog and we live in the country so not a lot of grass. But the colors are VERY dull. I love the way it looks when it’s wet. Is there anything you can do to make it look wet all the time? A sealer or something? It’s very hard to keep clean so I thought if there’s a sealer that is safe for text decking it would solve both problems.
    Thank you
    Debby
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    The Sealer Store · 05/23/2017
    bunnie:
    I have stained some composite decking. now I need to know what is the best sealer would be?

    Hello, you cannot apply a sealer over a deck stain.
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    bunnie · 05/23/2017
    I have stained some composite decking. now I need to know what is the best sealer would be?
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    The Sealer Store · 05/16/2017
    Sylvia Korte:
    All your tips on sealing composite decking seem to be referring to floor decking boards. My problem is railings and spindles, not the floor. I can't imagine how long it would take to apply a sealer to the railings around our deck in the way you suggest. But after numerous scrubbings and cleanings, the finish is much more porous than when it was first installed. It is 10 years old. Any suggestions?

    You can spray on the sealer with a pump sprayer. It is easy.
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    Sylvia Korte · 05/16/2017
    All your tips on sealing composite decking seem to be referring to floor decking boards. My problem is railings and spindles, not the floor. I can't imagine how long it would take to apply a sealer to the railings around our deck in the way you suggest. But after numerous scrubbings and cleanings, the finish is much more porous than when it was first installed. It is 10 years old. Any suggestions?
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    The Sealer Store · 06/24/2016
    We have sealers that will seal, but there is not a composite dealer that darkens the color.
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    Al Preston · 06/23/2016
    Do you (Sealer Store) have a stain/sealer product specifically "designed" to restore faded color and seal composite decking?
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    The Sealer Store · 06/23/2015
    No it does not.
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    Ted · 06/22/2015
    Does the sealers darken the decking material any?