The Problems with Composite Decking

By Scott Sidler • April 23, 2018

the problems with composite deckingThere are a lot of options for decking today. It’s not like the old days where you had to simply choose between different species of wood. Today, there are still all of the wood options of yesterday, but now there are scores of different composite decking options.

If you been a reader of my blog for any amount of time, you’re probably thinking “Oh now, here he goes again bemoaning another modern product.” Well, I want to tell you that that is not the case. I don’t have problems with new products, only subpar ones.

Sadly, most composite decking falls into that category. It has been improving slowly over the years with the introduction of capped products and other upgrades, but still, the reports from consumers and contractors are not promising. Take a look at some of the websites where homeowners have posted their reviews, and you’ll read 1 and 2 star reviews all day long.

The Problems With Composite Decking

There are a multitude of problems with composite decking that show up all too often to be just a stray issue for a hard to please homeowner. The accounts of issues are repeated with a frightening regularity and sameness throughout the threads of complaints. Below are some of the issues that crop up most often.


Especially prevalent on older and uncapped composited decking, mold shows up quickly and is more difficult to eradicate than you’d expect. The mold seems to grow heavily not just on the surface, but inside the rough texture of uncapped decking. It seems to come on strong and takes constant effort to keep the decking clear of it, especially for a self-proclaimed “no maintenance” product.

Color Fading

Everybody knows color fades in the sun, but composite decking companies seem to be oblivious to what their products are really capable of. Some composite decking has faded so quickly in just a couple of seasons that replacements boards stand out like a sore thumb. Just like the mold, this issue is unpredictable and hard to understand which decking will have problems and which will not.

Warping & Shrinking

It’s not wood, so it shouldn’t be expanding and moving the same, right? Right! It actually moves more AND more unexpectedly than wood decks. Some composite decking won’t move a bit and others have been found to shrink, swell, warp, twist, bow, and any other word you want to use in amounts unheard of, even with wood. Again, it seems completely random when this happens, but it happens often enough that you should know about it.


This one has been the issue that I encounter most- composite decking boards that feel like a trampoline when you walk on them. They have gotten so spongey that they sag from one board to the next making your decking like a mini rollercoaster. I notice this issue showing up after a decade or more of use, but it certainly shows up and when it does it usually makes the deck unusable. Check out the video below to see how springy these boards can really get!

What To Do?

For now, I’d say the best way to avoid problems with composite decking are to avoid it altogether and stick with wood. You may be one of the lucky ones who installs composite decking and gets away with it, or you may end up constantly on the phone trying to persuade them into the honoring their warranty, which is extremely hard to do.

Sure, wood has issues of its own, but it’s nothing that will take me by surprise. And if it needs a replacement piece, it’s as easy as swinging by the local lumber yard rather than trying to track down a model that has been discontinued 2 years ago from a supplier halfway across the country. As for me, I’m sticking with wood. How about you?

Composite decking has come a long way since it first came out, but it’s not there yet. Someday, the industry may be able to create a consistent long-lasting product that lives up to the claims, but right now, they can’t seem to make it work. When they can make a product that is consistently better than wood, then I’ll be in line for it, but until then I’m sticking with a reliable option like wood. How about you?

Share Away!

74 thoughts on “The Problems with Composite Decking”

  1. Hire a certified trex pro and use trex hidden fasteners. The spacing will stay as it should forever, or at least 20 to 25 years.
    You will pay more for the installation, but it is worth it! Your Trexpro will register your warranty. Trex has a hard time denying the warranty if your contractor follows the proper procedures. Sometimes the materials fail, but it is very rare at this point in the products life! Every material in the construction trade can have a bad manufacturing run. Decking, siding, windows, doors, or roofing. I have seen them all put out a bad product at one point or another in my 33 years+ as a carpenter. We have to hope that these failures have taught a lesson to the manufacturers.
    Your decking will only be a straight as the lumber you install it on. Wood will always warp, crack, and split. I am now using Trex Elevations light gauge steel framing for most of my projects. I have yet to see a warping board, or fascia when installed on Elevations. I would use Trex on my own deck, and recommend it over any other composite. I have installed them all! I do prefer Transcend over Select. It just has a better feel. Good luck to all of you, and use a certified professional!

  2. We’re in Texas and are in the design phase of a deck around our above ground pool. While we enjoy the covered wood deck on our house, we do not want the same level of upkeep around the pool. We will likely have a sun-sail type shade covering most of the decking, but heat definitely an issue. Has anyone installed Cali Bamboo Composite Decking or have experience with other types than Trex? I also read about Millboard based in the U.K., but no U.S. distributors yet. Thanks!

  3. My trex deck installation minimum gapping between pieces has closed up over time and filled in with pine needles and other debris. This is causing drainage problems and staining of the pieces is becoming very difficult to clean. What can be done to open up the gaps between runs? Considering Can running a skill saw with an 1/8” blade between each piece it to open up a gap for drainage?

    1. If the decking is capped then ripping it with a skill saw will reveal the uncapped portion which will cause more performance issues. Not sure if there is a solution other than cleaning out the needles consistently or removing the birds and reinstalling with bigger gaps.

    2. First we used a skill saw to create a gap between boards because some areas had none. Now about once a month I take a putty knife and push whatever debris either out of the gap or push it through the gap depending on the size of the debris. No pooling of water anymore. Much less mold and decomposing of the Trex material. Next up is painting it to seal the Trex better who approves of a product sold by Home Depot. Found it on their website.

      1. Could agree more with this article. We installed composite decking 12 years ago and will be tearing it up next spring. Boards are spongy and bounce and some have broken completely. The company we bought from declared bankruptcy but from what I have read I am staying clear. My friends pressure treated deck is going on 19 years with no issues. He treats it every other year and hasn’t had to replace a board. Going to build with pressure treated and use the new hidden fasteners. No need to screw the boards in from the top anymore. A 1/3 of the cost and it can’t be any worse than what we have. I have read that the warranties that come with composite are useless. Companies will use any excuse to avoid paying. Check out the complaints regarding TREX via the better business bureau.

  4. I have a Fiberon Deck that is failing miserably. The last two years it started cupping and splitting and the last two months has become a severe trip hazard. We spent over 15,000.00 on materials. Fiberon is now saying that it is because of a lack of ventilation. Their reps were out here prior to even laying the product to inspect the infrastructure as I wanted a diagonal deck. My deck is 8 years old. I am going to start a media blitz about all of this garbage. Fiberon was here 4 times during our installation. I just found out yesterday that their composite deck is a wood byproduct that is wrapped in vinyl. Did anyone else know this.

  5. Yankee Lady and Foothill Family posted almost identical reviews (“Trex has a life of its own, and behave better when horizontal”) less than 12 hours apart. Someone is poisoning the well here.

  6. I have been in business for a very long time and I will be the last one to say that the customer is always right and in most cases they are not but having said that. I am a firm believer in standing behind your product and services. I built my house in 2002 and its consider a high end build in my area of the country and the builder I used was considered one of the best. They used Trex decking on both deck top and bottom. The lower deck looks like a skate park. It has warped really bad. I have reached out to Trex and they won’t cover the problem because they say it’s the joist underneath that’s causing the problem along with the boards being to close together. When they constructed this house it was done right including the deck. I know how a deck is to be installed including Trex and it was done correctly. Just like pressure treated wood decking you still have to pressure wash the boards to keep them clean. If the claim is maintenance free I dont know where. My advice would be to stick to traditional wood. This is obviously a product that is inferior and until they can perfect the product save yourself some time and money and use wood for your decks.

    1. Or use Millboard! You don’t get any of these problems you are all moaning about, but..there is a catch…..they don’t supply into the US yet.

  7. We had a Fiberon deck installed two years ago. It has been nothing but a problem since then. The boards had a “dusty, dirty” look to them and nothing would clean them up. We contacted the manufacturer and got no help at all other than to tell us that we should buy a cleaner they recommended. We did that and it did nothing. Even our dog’s footprints will not clean up. We are so disappointed and would never recommend this decking or this company to anyone. We spent a lot of money to have a “trouble free” deck and in the past two years we have spent more time trying to get this one clean than in all of the past 42 years we have been in this house with wood decks.

  8. My trex deck is warping badly this season. It’s about twenty years old so I don’t know if I should have it ripped out and new deck put in

  9. Hello all who have posted here!
    I hear you frustrations and concerns and feel for you. If you could encourage someone in America to consider importing Millboard decking I can promise you you would not get the issues your talking about. Without sounding like I’m selling Millboard is made from resin rather than plastic and didn’t react to temperatures like plastic does. We have been importing to Australia and the Middle East for about 6/7 years now and though Millboard does get hotter than timber it’s not as hot as plastic, but the amazing thing about it is that it doesn’t move like plastic does, is expand Inthe heat and become soft or shrink in the cold and become brittle. It contains no protein based materials like wood flour/dust, rice husk, bamboo fibre to feed the growth of miss/algee or black mould and is totally non porous. This makes it genuinely low maintenance and in fact the more rain you get on it the better as it helps to wash it down. I would encourage you to look up
    I seriously feel sorry for you folks facing these issues as there is a solution.

    Kind Regards

  10. We had our deck replaced last July, and chose Trex Select. Since that time, the fascia board around the perimeter of the deck appears to have warped and the mitred corners have separated. The fascia board used along the sides of the stairway also seemed to twist.

    Our contractor has replaced the fascia boards along the side of the stairway about a week ago, and it already appears to be “rippling” in between the areas where fasteners are affixed. He plans on replacing the fascia board around the deck perimeter, but I am concerned that we will have a recurring problem. I am considering just having them replace the fascia with wood and keep the Trex on the deck flooring and steps. It seems as if Trex has a life of its own, and behave better when horizontal but does peculiar things when used in a vertical application. Any ideas?

  11. After a lot of thought, we replaced the old deck on our house last July. We decided on Trex after researching and noting that the previous problems were seemingly resolved. The deck flooring and steps were Trex Select, and the sides of the deck and stairway were Trex fascia board.

    Since then, the fascia board on the sides has bowed creating a large gap at the 45 degree mitered corners. The sun-exposed side of the stairway had bowed. Our contractor came out and has replaced the board on the side of the stairs, but within less than two weeks, it is buckling up in between the areas with fasteners! The contractor has suggested that more fasteners will fix the problem, but I sense that Trex has a life of its own and seems to behave when it is horizontal vs with vertical or oblique uses. Has this been noted? I am about ready to have them remove all the fascia board and just replace it with wood.

    1. My husband has installed our co posited decking and after 2 weeks with all the rain we have had it’s fading but we were told this that it would fade by 15% in 2. Months ,scratches easily , you can only clean it with soapy warm water , as I tried cleaning a stain with white spirits and some of the decking has gone a lighter colour , wouldn’t buy it again

  12. Like Laurie, our experience with Trex has been good. I’m not sure what level of Trex we have – likely Select – but we’ve had it for about 10 years now. No problem with warping or fading. The deck was poorly built, without enough space between slats to drain water, so water collects on it and it gets dirty and mossy, but power-washing cleans it well.

  13. I am very confused now . I thought by going to composite , my problems would be over . My wife and I are also retired and trying to get away from the work involved with a deck We have already torn our old deck apart . It is a 20 x 24 deck to be done . Is there a wood that can be used that does not require a lot of staining and maintenance .
    Our deck get lots of sun for the better part of the morning . We live in Canada ,so are winter are harsh and our summer here are always filled with sunlight . So confused . HELP .

    1. Carlo! All I can say – we’re in the same situation. We were going to install composing decking but after all of these reviews, I’m absolutely lost.

Leave a comment!

Keep the conversation going! Your email address will not be published.


This site uses Akismet to reduce spam. Learn how your comment data is processed.