Composite Trex decking, made of a combination of plastic and sawdust, is considered one of the top composite decking alternatives available. However, in recent years Trex decking has battled lawsuits concerning issues with the decking. Examine the possible issues with this composite decking to determine if it is the proper solution on a case-by-case basis.
Claims made by Trex that the composite decking materials will turn silver with age and weather are found to be false. Instead the weathered composite turns to a musty gray color. That's fine if a gray deck is the end result in mind, but there is a large difference between gray and silver.
Resins leach out of the surface of Trex decking, leaving small gaps where the sawdust (part of the composite) is exposed to the air and moisture, which results in a nasty black mildew that you cannot remove, even with bleach, because the organic material (wood sawdust) that promotes the growth of the mold is still viable below the surface of the decking.
As the Trex decking ages, the resins leach out. Again, those small pockets of exposed sawdust are created. Anything that can stain a surface, such as dog or cat urine, food substances, or berries, leaves and acorns from overhead trees, will stain the sawdust of the Trex decking. These stains aren't removable because they aren't on top of the decking but are inside the small pockets left by the leaching resin.
Due to the exposure of the sawdust in the Trex composite decking, moisture can cause the decking to swell and consequently buckle. Trex decking is attached from the underside, so the buckling of the planks make it look like corrugated cardboard. This moisture that causes the buckling seeps into the small pockets left by leached resin and swells the sawdust, causing it to become larger than usual. Once buckling is noticed, it is too late to repair the damage; you must replace the planks.