How Much Does a Composite Deck Cost?

Composite Deck Installation Cost Range

Composite decking prices are typically between $15 – $65 per square foot when installed by a pro deck contractor. The cost varies based on the size of the deck, the specific brand and style of decking you choose, whether deck railings and the substructure is built with composite materials, and of course who builds your deck.

Average Installed Cost

While the cost range is quite wide, most composite decks cost an average of around $35 per square foot when a treated wood substructure is used and the deck has railings and a short set of stairs. This includes professional installation.

Overview of Composite Decks

Composite decking is growing in popularity because it is more durable than wood and requires far less maintenance. They make it the perfect choice to install around an above ground pool or other backyard feature that you prefer not to spend hours each season pressure washing or re-sealing.

The cost of a composite deck varies greatly with the specific type of composite, and the fact decks can have rails or no rails. Other composite decking price factors are discussed below.

The cost differences in composite decking are shown in the Retail Cost section below. Sample project costs including materials and installation give bring material and labor cost factors together in a package, including the cost of composite railings around your deck.

Finally, actual project costs submitted by homeowners give real examples of what others have paid. With that in mind, consider bookmarking Costimates and returning to share your deck cost for the benefit of other readers.

Composite Deck Installation Cost Factors

As noted, contractor installed composite decks run $22 – $33 per square foot. Using the Trex Cost Calculator shows that supplies alone will exceed that cost range.

Here are the keys to the cost of a composite deck.

• Specific Decking Used – Brands like Trex and TimberTech make basic, better and best grades of decking. Quality is mostly based on the decking material used, such as polymer or cheaper plastic composite and whether all sides are capped. For example, Trex’s best series, Transcend, costs 75% more than its entry-level Trex Select decking. TimberTech Pro Legacy costs more than twice what TimberTech Edge costs. That’s the case when comparing Azek Vintage with Azek Harvest.
• Whether your Deck Has Rails – Composite deck rails add 40% to 55% to the cost of a composite deck. Decorative post caps, wider top rail, aluminum deck rails and other accessories factor into total rail cost.
• Deck Thickness – Some brands offer thickness options. It’s standard planks are about .8” thick. It sells what it calls a 2” plank that is 1.3” thick.
• Substructure Factors – There are two. Occasionally, an existing substructure can be used for the new deck boards. If you’re deck includes a new substructure, using pressure treated pine is a common way to save money versus using composite.
• Deck Complexity – A rectangular deck with boards running parallel to the house is an easy installation compared with an octagonal deck or one with boards running diagonally. Whenever installation is more difficult, cost goes up.
• Deck Size – Obviously, the larger a deck is, the more it will cost. However, cost per square foot drops slightly as size increases.
• DIY vs Pro Installation – Labor costs represent 20% – 40% of the cost based on the composite deck line you choose. That’s what you can save with DIY installation. Specific labor cost per square foot are discussed below.
• Extra Features – If you want electricity run around the railings for lighting, it’s going to add. Built in seating does the same. Adding a retractable patio awning is a common feature that will also increase the cost to build a deck on your home.
• Site Leveling Work – If the area you want your deck needs to be leveled or graded, expect the installed cost to rise by $250 to $1,000 or more depending on the size of the area. Learn more about grading and clearing costs.
• Time of Year – Having a deck built in the off-season, when contractors are less busy, could bring lower cost estimates.
• Cost of Living – Generally prices in your area, low, high or average, will affect composite deck cost too.

Cost of Decking and Installation Supplies

Sometimes homeowners shop deck boards, see composite deck cost per square foot, multiply by the size deck they want and expect that to be the total cost. The true cost of a composite deck is far from that simple.

Here are retail costs that will assist you in estimating total cost. Let’s start from the ground up.

• $1.75 – $2.25 per square foot | Cost of pressure-treated lumber plus concrete piers for the substructure.
• $5.25 – $6.50 per square foot | Cost of composite substructure materials. Most composite decks are built using a wood substructure. Trex Elevations is one brand of composite substructure, and it costs about three times what a wood deck costs.
• $4.00 to $12.00 per square foot | Cost of Deck Boards. The factors above explain the wide cost range. Note: Most deck boards are priced by the plank. To determine square feet, multiply the width x the length in inches and divide by 144. If the board is 5.5” or 6”, which most are, you can also simply divide board length by 2.
• $30.00 – $55.00 per linear foot | Composite Deck Rail Materials, based on type and style. If a rectangular deck is attached to the house, then it has rail on three sides. Add up the length of those sides and multiply by the cost per linear foot.

Sample Composite Deck Project Costs

Let’s look at three projects and three levels of decking quality using a 400 square foot, or 20 x 20 foot deck for each.

The first cost is without rails, the second with rails.

Basic Quality Composite Decking

• Easy Rectangle: $4,800/$6,700
• Average L-Shaped: $5,700/$8,550
• Complex Design: $6,800/$9,800

Average without rails: $12.00 – $17.00/square foot

Average with rails: $16.75 – $24.50/square foot

Better Quality Composite Decking

• Easy Rectangle: $6,200/$9,300
• Average L-Shaped: $7,700/$11,500
• Complex Design: $9,200/$13,500

Average without rails: $15.50 – $23.00/square foot

Average with rails: $21.75 – $33.75/square foot

Best Quality Composite Decking

• Easy Rectangle: $8,600/$12,500
• Average L-Shaped: $9,450/$13,750
• Complex Design: $10,500/$14,800

Average without rails: $21.50 – $26.25/square foot

Average with rails: $30.50 – $37.00/square foot

Old Deck Removal Cost

Wood or composite deck removal and disposal costs $1.25 – $2.50 per square foot. If you DIY, a good option is to rent a small dumpster for the disposal.

Permits, Inspection, Related Costs and Installation Time

Permits and Inspection Cost

• $30 – $100 | You’ll need to pull a permit so that the deck substructure and completed deck can be inspected.

Installation Labor Costs and Time

Contractors charge by the job instead of by the hour. Depending on deck difficulty, it breaks down to:

• $4.50 – $7.50 per square foot | Installation labor cost to install a deck.

Cost varies based on whether a handyman or a decking contractor does the work and how difficult the installation is.

Homewyse pegs labor a little higher but emphasizes that deck complexity is the largest factor. The site estimates that difficult design doubles the time and therefore the labor cost of installation from about $4.00 to about $8.00 per square foot.

Here are typical time frames for the 400 square foot decks estimated above installed by a crew of 2-3 people.

• 2.5-4 Days | Easy Rectangular Deck
• 4-6 Days | Average L-shaped Deck
• 5-7 Days | Complex Deck Design

Related Deck Projects

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DIY or Hire a Pro?

Decks are a common outdoor project for homeowners with good carpentry skills. Keep in mind that it is a big project that has to be planned carefully and done properly. It will be inspected, and you of course want it to be safe.

Lowes has a series of videos on basic deck building that might help you decide whether DIY is your best approach. Composite decking has a few unique challenges like the need to pre-drill fastener holes. This 5-minute video from TimberTech shows how to install decking with a grooved profile. The groove allows you do use concealed fasteners. If you choose square planks, the fasteners will be driven through the top of the planks.