A deck can last anywhere from 10 to 30 years if made from untreated wood and can last as long as 50 years for treated wood or composite materials. Because a deck is a long-term investment and you will be enjoying it for decades to come, it's important to understand your choice of materials before starting your building project.
Both wood and composite materials come in low and high quality, so cost or quality is not the only factor. It's commonly known that composite materials require less maintenance, hence, their cost is usually higher. But they do require some maintenance, and other factors come into play as well. Let's look at some of the issues involved in choosing the right deck material for your deck.
Many people prefer real wood for their decks because of its natural, warm appearance. It just feels good.
But there's wood...and then there's wood. The type of lumber you choose for a wooden deck is critically important to the longevity and level of maintenance of your deck.
A common and inexpensive option is to go with treated lumber, also called PT for pressure-treated. PT wood is made of fir soaked in anti-rot and insecticide agents. Its natural color is a somewhat brown-green, but you can stain it for a more attractive color. But there's a reason that this is the most inexpensive option for decking: it's susceptible to warping, splitting and cracking, so it requires regular maintenance.
If you want the natural route, go with a weather-resistant wood such as cedar or redwood. These types of decks have a beautiful look-and-feel and resist warping, cracking or other weather damage. Redwood is usually more expensive than cedar and in general, these types of decks come in at about three times the price of treated lumber.
A very expensive hardwood also used for decks is ipe, which is also naturally resistant to rot but is a harder wood and therefore more durable than either cedar or redwood. Ipe can cost up to four times the price of the cedar/redwood option because it is imported from South America.
Gaining in popularity are composite decking materials, composed primarily of a mix of recycled plastic and wood fibers. While a deck built with these materials is clearly not "natural" and won't have the potential beauty of a real-wood deck, you can choose from an array of colors to mimic a more natural look. Further, advancements in this type of decking have made its look-and-feel downright attractive, by many accounts.
The strongest argument for composite materials is their low-maintenance requirement: no sanding, refinishing or staining—ever. Further, it usually comes with at least a 20-year warranty if not a lifetime guarantee. The downside is—as you might expect—its cost, which runs approximately twice that of natural wood decks, depending on the quality and warranty.
All decks, including composite, require some maintenance. Natural wood decks are the most demanding, requiring annual refinishing, which sometimes means sanding, removal of last year's finish, and application of a new finish. If you love the look of natural wood and you're up for the upkeep, it's definitely worth it.
Pressure-treated wood requires refinishing with a clear sealer or stain every other year, just half the maintenance of a natural wood deck.
For composite-material decks, no refinishing is required, but the materials can become hosts for mold if they are not cleaned at least every three or four years.