Traditionally, most backyard decks have been constructed of treated yellow pine. A smaller percentage have also been built of untreated cedar or redwood, which are usually chosen to due to their natural decay resistance.
The major problems with all solid wood decks are:
(1) They require annual maintenance (cleaning and a good application of a high quality sealer) to keep them attractive and structurally sound,
(2) They have problems such as cracking, splitting, warping and the growth of mold and mildew, and
(3) They use virgin wood, which is usually not grown in a long-term sustainable fashion, especially redwood and western cedar, which are generally cut from old-growth forests.
In addition, treated wood (which is usually southern yellow pine treated with CCA, chromated copper arsenate) has environmental and health issues associated with its production, use, and disposal (See the Wood Treatment section in this Sourcebook for further information).
The alternative materials described herein usually are made of 90-100% recycled materials, which reduces our landfill space and the need to extract and process virgin wood. They also do not require any use of sealers or paints and are thereby considered to be maintenance-free. They do not suffer from any of the traditional issues with wood, such as cracking, splitting, or warping.
Austin suppliers have a number of types of alternative deck materials ready for purchase. All offer attractive, durable and maintenance-free decks, porches, walkways, docks, etc. Regarding installation, they can be cut, routed, nailed, drilled, and screwed in the same fashion as wood. Their only difference is that they usually have a lower structural value than their wood counterparts, and so, usually require narrower spacing between their support beams or joists. A typical 2x6 piece of solid lumber will span up to 24" on center, whereas a typical piece of 2x6 piece of composite lumber will span up to 16" on center. It is important to check with each manufacturer, though, because they will have their recommended spacing specified.
The two most common types are wood/plastic composite lumber and 100% plastic lumber.
Composite Lumber is usually a composite of wood waste/recycled plastic. Various products are available at local retail outlets. They also look very similar to regular wood and usually weather to a grey color.
Plastic Lumber is 100% recycled plastic lumber usually from PET, HDPE or LDPE and is available in a number of non-fading colors. It has a similar workability to wood, but may tend to expand more in high temperatures. There are no local retailers of this material at this time. Orders from national suppliers are available.
No-maintenance deck materials are more expensive than traditional ones on a first-cost basis. The first-cost of alternatives are different for each manufacturer, but they are generally 40-150% more than treated pine, 0-100% more than western cedar, and 20% less than to 60% more than redwood. Although these percentages may seem like a large difference, the total dollar amount is for most decks, not that great. When one considers the avoided annual maintenance activities and costs, these materials quickly pay for themselves in a couple of years. Annual applications of waterproofing will cost a do-it-yourselfer at least $.20 per square foot for materials and hours of labor on purchasing the materials, applying deck cleaner, scrubbing, rinsing, and applying the sealer. A professional will charge $1 per square foot to clean and reseal a typical, simple deck. Some of the alternative materials cost $1 per square foot more than the treated pine, so in one year, the extra cost is paid for.