A deck is a flat surface capable of supporting weight, similar to a floor, but typically constructed outdoors, often elevated from the ground, and usually connected to a building. The term is a generalization of decks as found on ships.
Functions and materials
Wood or timber “decking” can be used in a number of ways: as part of garden landscaping, to extend living areas of houses, and as an alternative to stone based features such as patios. Decks are made from treated lumber, composite lumber, composite material, and Aluminum.
Historically, the softwoods used for decking were logged from old growth forests.
Decks are often built from pressure treated wood. Pressure treated wood is long-lasting and holds up to wet and icy weather conditions. Pressure treated wood however is treated with chemicals. It is also important to note that both softwood and hardwood decks will need to be finished after installation using either an oil or varnish to prevent weathering, wear, mould, algae and wood boring insects.
The deck of a house is generally a wooden platform built above the ground and connected to the main building. It is generally enclosed by a railing for safety. Access may be from the house through doors and from the ground via a stairway. Residential decks can be constructed over steep areas or rough ground that is otherwise unusable. Decks can also be covered by a canopy or pergola to control sunlight.
Typical construction is either of a post and beam architecture, or a cantilever construction. The post and beam construction relies on posts anchored to piers in the ground. Typically, these types of structural decks are engineered and require an experienced construction company that specializes in structural decks. Cantilever decks rely on floor joists that protrude out further than the wall of the house. While this type of construction is common, it raises significant safety issues if the decks are not properly waterproofed and flashed.
Typical railing assemblies must meet structural strength requirements of 200lbs of load force per foot. In short, decks are complex load bearing structures that most often require structural engineering, plans, and permits.
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 Brazilian ipe wood, 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.