One of the first choices to wood decking was Trex’s original product. They encountered problems with it and in 2009, they were faced by a class action lawsuit for flaking as well as mold-spotting on their boards which were resolved through a settlement. Newer Trex products have improved and do not have the same problems they had in 2009. They however also cost more and are not completely free from problems. Hence, it is advisable to be aware of some troubleshooting know-how if you own Trex decking.
Mold spots on the deck
Right after the lawsuit in 2009 was resolved, a technical bulletin was issued by Trex wherein they explained that the development of molds on any wood product is a natural occurrence. They provided a way to deal with the problem by using a solution with sodium hypochlorite bleach in washing the deck. They educated the public regarding the negative effect involved in doing this: the color will slightly lighten after the solution is applied. Molds however, only appear in composite decking where an amalgam of wood chips as well as plastic is used to construct it. For mold-free decking, there is PVC and cap stock decking which has a layer of plastic to enclose the composite.
Bad-looking stains may develop on a composite deck due to sticks, leaves as well as other debris that may collect on it. Tannin deposits left by these materials seep down the composite deck and stay there. These have to be removed to avoid stains from developing. The Trex company suggests using a deck brightening liquid containing oxalic or phosphoric acid in washing the deck. Water pressure can also be used in washing the cap stock Transcend boards or Trex Enhance. Just take care that the pressure does not go beyond 1500 psi so as not to void the warranty. These two (2) are the only Trex products you can pressure-wash. You cannot use this type of washing on any other Trex product because the warranty will surely be voided, and it might leave behind gouges or cause a board to flake off.
The boards can acquire a washed-out look and the color also fades after being exposed to sunlight for many years or after having applied a brightening agent. Using a stain meant only for composite decking can restore the color. Apply a single coat of composite stain using a roller or a brush. Wait for thirty (30) minutes, and then remove any stain that may have collected on the deck. Otherwise, it will be difficult to get rid of it because it would have dried to a sticky evenness. It is classified as a high-solids product which gives a semi-transparent coat or finish and binds to boards’ surfaces.
Composite boards is known to be not resistant to moisture. It can weaken the bonds of the wood particles when it seeps inside. Internal splitting or flaking may result from this, and this becomes evident on board ends. Replacing the boards that have been affected is the only way to deal with this problem. Unfortunately, all boards including PVC types are exposed to, and react in the same way to moisture. They expand and if these boards are placed too close together, this can cause cupping and warping due to loosened fasteners. In this case, the boards have to be re-installed with new fasteners as well as placing a wider distance between each one of the boards.