Decking made from a mix of plastic and wood--such as Trex, ChoiceDek, and TimberTech--is an excellent alternative to wood because it won't warp, rot, or splinter. Plus, these products withstand termites and other bugs, offer a uniform color, and won't fade, so you don't need to fuss with stains or sealers. Because wood composites are water resistant, they're perfect for docks and other surfaces near the water.
The composites do have a couple of drawbacks. They are somewhat more expensive than pressure-treated wood and aren't as structurally sound. Use them only for the decking surface or as handrails; never use wood composites to frame a deck or as structural supports. This material falls in the price range of $4 to $5 per square foot.
Cedar and Redwood
These woods are known for their natural resistance to disease and rot. They're both durable and easy to cut, but because they are soft, cedar and redwood can split. Predrilling holes is a good idea. They can also be scratched or gouged by sliding furniture across the surfaces. Both woods are quick to weather and gray, so applying a sealer with UV protection is a must. Some sizes may also be difficult to find. Cedar and redwood fall in the price range of $4 to $6 per square foot.
Mahogany and ipe are high-end options. Mahogany has a tight grain and is naturally a beautiful red color. Only purchase mahogany that's been harvested from a managed forest because certain species are endangered. A great material for the floor of a covered porch, it should be sealed to keep it from cracking and splintering. Mahogany is the most reasonably priced of the exotic woods at around $4 per square foot.
Ipe is incredibly dense, which means it only needs to be sealed once. It's virtually knot- and splinter-free, weathers beautifully, and is impervious to bugs and rot. It's an expensive option at $5 to $6 per square foot and must be predrilled, which drives up labor costs.
Several years ago, concerns surfaced about this material being a health risk because certain chemicals used to treat the wood could leach into soil. After exhaustive testing by the EPA, pine industry, and other organizations, it was determined that the amount of arsenic in soil was miniscule and really posed no human health risks. However, the wood industry has changed its pressure-treating process. For residential use, all chromated copper arsenate (CCA) lumber should be pulled from the shelves and replaced with alkaline copper quaternary (ACQ) by this spring.
There's no need to pull out your existing lumber to replace it, but this process should remove any doubt or concern about pressure-treated wood. The new lumber will perform in the exact same way as the pressure-treated pine you're used to--perhaps even better. You can place nails or screws in it, stain it, and seal it like you always have. Some retailers have raised the price, but it's still the most affordable option at $2 to $3 per square foot.
It's a good idea to seal pressure-treated wood annually. Also, always let new wood dry for at least six months prior to staining or sealing it.
Keeping Your Deck in Shape