Adding a deck to your property is a solid investment in your home. But decks do more than increase the monetary value of your property. Decks help extend your living space from the inside to the outside, giving you more room for cooking, relaxing, and socializing. You'll want to know the average cost to build a deck—before you make that first call to a contractor.
Cost to Build a Wood Floor Deck
Real wood has long been used for decks' structural members and for its flooring. Wood is cost-effective, strong, easily available, and it can be stained to a wide range of colors.
At the same time, wood must be painted or sealed at least once a year. Wood can be hazardous underfoot as it begins to rot and splinter. Wood attracts wood-boring insects such as termites and carpenter ants. Finally, wood is not an eco-friendly choice since it requires the milling of large logs.
The most basic type of deck employs pressure-treated wood for nearly all elements of the deck: joists, posts, and floor boards. Metal joist hangers are used to connect the joists to the beams. Non-corrosive deck screws are used to connect the floor boards to the joists.
It costs between $45 and $47 per square foot, on average, to build a deck with pressure-treated wood flooring, including materials and labor.
For a deck measuring 16 feet by 20 feet, for a total of 320 square feet, plus a couple of simple built-in benches, a few stairs, and railing, expect to pay between $14,000 and $15,000, averaged out across the United States.
Costs do vary across the U.S. Along the West Coast, a similar job may cost about $2,000 more than the average ($16,000 to $17,000). In the Midwest, you may pay about $1,000 less than the average ($13,000 to $14,000).
High-quality exotic wood deck materials instead of pressure-treated wood will further increase the cost of the deck. One desirable exotic species, ipe wood, costs $17 to $20 per square foot, minimum, materials only. These super-hard woods, too, require special hidden fasteners, which can further drive the cost upward.
Cost to Build a Composite Floor Deck
Wood composite decking is made from wood byproducts and recycled plastics. With some brands, as much as 95-percent of the wood composite is derived from recycled materials. Wood composite doesn't rot, split, crack, or need staining or painting. Wood composite flooring is smooth underfoot, so it lends itself well to homes with children and pets, or just about anyone who likes to sit barefoot on a deck.
Wood composite decking costs about $9 to $15 per square foot, materials only. Compared to pressure-treated wood flooring, which costs between $2.50 and $4.00 per square foot, composite flooring is about four times more expensive than pressure-treated wood flooring. But wood composite is still generally less expensive than premium exotic wood species like ipe.
Basic quality wood composite flooring on a deck with railing, atop an existing substructure, will cost around $1,100 to $1,200 for 100 square feet. Mid-range quality wood composite with a similar installation profile will cost $1,900 to $2,000. Top-quality wood composite flooring for this project will cost $2,200 to $2,300.
Wood composite flooring decks are more expensive than decks with pressure-treated flooring in a couple of ways. Composite wood itself is more expensive than wood on a square foot basis. Since composite wood is not as strong as wood, more joists are required to create shorter spans between the joists.
It costs between $59 and $63 per square foot, on average, to build a deck with composite wood flooring, including materials and labor.
Across the U.S., you will pay about $19,000 to $20,000 for a wood composite floor deck measuring 16 feet by 20 feet plus a built-in bench, stairs, and railing. The cost rises to $22,000 to $23,000 along the West Coast but drops to $18,000 to $19,000 in the Midwest.
Cost to Build a Floating Deck
A floating deck can be a good alternative to build a deck while avoiding the high costs associated with building large-scale decks.
Most decks are attached to the house with a ledger board. By contrast, a floating deck is detached from the house and can even be located well away from the home. Floating decks rise no higher than 30 inches. In many communities, building permits are not required for floating decks that remain at or below that level.
Because less wood is needed for the build and because the deck does not require concrete posts, the cost for a floating deck will be far cheaper than for other types of decks. For a do-it-yourself detached deck, 10-foot by 10-foot, expect to pay between $300 and $600 when using pressure-treated wood for both the supports and for the flooring.
Wood Destroying Organisms. College of Tropical Agriculture and Human Resources, University of Hawai'i at Manoa.