Wooden decks are made from treated lumbers: red cedar, mahogany and other hardwoods. Few aspects of a home require as much maintenance as a wood deck. Exposed to the elements, a wood deck needs sanding, resealing or painting to maintain the desired look and to hold up over time. Although treated wood retains certain resistance properties, moisture and insects still attack, and most wood gives in to rot over time.
Many decks are made of pressure treated pine. Good quality treated pine will last thirty years or so before there is any substantial decay. However, discoloration and splintering can begin after only a few months. For this reason, most people take on a regular cycle of maintenance. Failure to do so won’t cause your deck to rot, but your deck will most certainly become discolored and the surface will become rough and prone to splinters.
Wood-plastic composite decking is comprised mostly of recycled cellulose-based fillers like wood fibers from recovered saw dust, peanut hulls, bamboo, and straw. Added to these natural ingredients are waste plastics like polyethylene and PVC.
The composites and wood products are mixed to a doughy 50/50 (up to 70/30) consistency, with stabilizers, colorants, and lubricants added as necessary depending on the application. The mixture may be hollow or solid, and can be shaped using traditional wood-working products.
The benefits of composite over wood are rot, insect, and moisture resistance, and better stain hold. They do not crack or split, and are often warranted for ten years against the need to re-seal and re-paint. Because of the recycled nature of the product, these composites are more environmentally-friendly than wood decking, and require less maintenance.
Some problems are that these products are heat sensitive and may warp more easily than wood, and that they can be twice as expensive as traditional wood. Mold and mildew are also enemies of composite decking. These problems can be dealt with using proper board spacing (to improve drainage) and plastics cleansers.
Although not a wood composite, plastic decking is another option. Plastic decking may be comprised of 93 per cent recycled plastics like milk jugs, with 7 per cent fiberglass. Unlike composite decking, plastic decking stain will not fade, and will not absorb water. Again, the cost is prohibitive, being up to four times as much as wood decking.