Composite or synthetic decking is the ultimate choice for a low-maintenance, long-lasting deck. Learn about decking choices for building your new deck.
Low-maintenance decking is good news. Traditional wood decks look great, but you have to refinish or reseal them every few years to keep them looking that way. Low-maintenance alternatives now promise much of the same look and feel of wood, but without the worry that they'll crack, split or warp if you neglect them.
Wood composites (mixtures of wood fiber and plastic) are leading the way. We'll introduce you to two types of composites—solid boards and a variety of hollow shapes. We'll also tell you about vinyl and aluminum decking options that require even less maintenance than composites.
Solid composites look the most like real wood
Solid composites look and handle much like wood but resist rot and need less maintenance. They're available in a range of sizes, although 1-1/4 in. x 5-1/2 in. is most common. In sunlight, colors tend to fade toward light gray.
If you like the look of a traditional wood deck, solid composites are for you. They imitate the look, feel and workability of wood deck boards. They're roughly the same size— about 1 to 1-1/4 in. thick and 5-1/2 in. wide. They're tough and durable, and they resist insect and rot. The finished deck will have a solid feel underfoot with minimal flex. Every composite board is identical and flat, without twists, warps or knots to slow installation time. However, composites may require an annual cleaning to remove mildew and dirt. They aren't structural (use wood joists).And solid composites are heavy; they're a chore to handle if you're working alone.
Cut, shape and sand composites with regular woodworking tools. Use carbide blades.
If you're accustomed to working with wood, it's easy to make the transition to solid composites. You can cut a board with a circular saw, round over the edge to a bull nose with a router, and soften the ends or erase a scratch with a sander. Use a 24-tooth carbide circular saw blade and carbide router bits (high-speed steel dulls quickly). Frame your deck with pressure-treated wood joists 16 in. on center (12 in. on center (o.c.) if you set the decking at a 45-degree angle).
There are a myriad of fastening systems to choose from. From hidden fasteners to simple screws.
Solid composites are tough, so driving the fasteners requires oomph. Use either 2-1/2-in. screws or 2-1/2-in. nails. Most screws cause the surface to bulge or mushroom. You can either whack the lump down with a hammer or prevent it by predrilling and countersinking a hole before driving the screw.
Composites are flexible, offering cool design options for curved decks.
Composites are surprisingly flexible, making them ideal for decks with curves. Here are a few tips for bending boards:
Solid composites also work well for a ground-level deck where there's high moisture and minimal airflow. They'll resist cupping and warping and won't rot.
Timber Tech is one brand of hollow, lightweight decking with a novel fastening system
Composite varieties include profiles that are hollow and thinner, and connect with tongues and grooves (and hidden fasteners). Surface textures vary.
Consider one of these systems if you want a lighter-weight composite, a tightly spaced appearance or a simple hidden fastening system. Interlocking tongue-and-groove systems eliminate gaps and allow you to hide the screws as well as drive fewer of them. Several styles are stiffer and can span joists on 24-in. centers. However, each system has “need-to-know details” to make the job successful, including how to cover the ends of the boards, how to rip boards, where to start the first board, and where and how to fasten them. Many require at least a 12-in. air space under the deck for ventilation. Study the details of each system at the lumberyard or home center before buying.
Most varieties require extra trim to cover the unsightly exposed ends. The last board may require reinforcement.
Like the solid versions, these composites are cut with normal carpentry tools. Installation details vary by brand; study them before you start. Ripped boards may require reinforcement. Cover the ends with special trim pieces from the manufacturer or a trim board. If using tongue-and-groove boards, slope the framing 1/2 in. over 8 ft. to drain any water away from the house, and run the decking perpendicular to the house if possible.
Screw placement is critical for each composite system. Tongue-and-groove systems allow you to hide the screwheads.
Tighter spacing and tongue-and-groove systems create a slightly different deck appearance and partially shed water.
The tongue-and-groove style looks tight and clean (no fasteners) and partially protects the space beneath from rain. The lighter weight boards are easier to handle and are often more suitable for rooftop decks. Some tongue-and-groove versions fit tightly and look more like a porch floor than a deck.
Fastening systems vary, but all feature hidden screws.
Vinyl requires even less maintenance than composites. Simply rinse it down with the spray of a garden hose and you've got a fresh, clean look. Colors (tan, white and gray) resist fading much better too. It's lightweight and most brands have a hidden fastening method, usually screws that you fasten to a treated wood frame. Vinyl won't look or feel like wood or the composites. When you walk across the deck, there's a lighter, hollow sound. It blends well with vinyl siding.
Although not difficult to install, vinyl systems aren't as versatile as composites. While you can cut it with a circular saw, installing it is more of an assembly project. You'll need special end caps and other detail pieces. You have to plan carefully. Vinyl railings that complement the deck are also available. Many manufacturers back the vinyl with lifetime warranties.
This decking interlocks to provide a watertight space underneath.
If you want a dry space under a deck and a maintenance-free, lifetime deck surface, aluminum is a really cool option. It doesn't look like a traditional wood deck, however. It's heavy-gauge metal with a coated finish available in white, gray, almond and tan. The “boards” interlock into a gutter system that catches water and channels it away. Since it's a kit-type system, you have to order all the parts. Railing kits are available. Aluminum decking can span joists up to 30 in. on center, but it feels extremely stiff underfoot. It's not as hot in direct sunlight as you might think; the light colors reflect the sun and aluminum disperses heat very well.
You screw aluminum decking to standard treated wood framing, set to slope at least 1/8 in. per foot away from the house. You'll need special starting and finishing pieces, as well as trim pieces to cover the ends. You can cut aluminum with a circular saw equipped with a 40-tooth nonferrous metal-cutting blade, but it's slow and loud. If possible, avoid cutting by framing your deck to accommodate full-length deck panels, and stick to simple, rectangular decks.