Composite decking has moved from an alternative product to the default choice on many new decks. Builders and homeowners now face a board market with capped and uncapped options, hollow and solid profiles, and price gaps that can double the cost of a project. The material is roughly half wood fiber and half recycled plastic, and that blend explains both its durability and its quirks. Knowing what is inside the board, how it behaves when cut, and how it reacts to weather separates a deck that looks good for decades from one that warps, stains, or fades within a few seasons.
The same material logic applies one level down, where metal floor decking carries loads on commercial projects and composite boards carry foot traffic on residential ones. Both products ask the installer to respect the manufacturer’s spacing and fastening rules, because a board only performs as well as the structure underneath it.
What Composite Decking Is Made Of
The basics of composite decking start with the raw materials. Composite boards begin as a mix of wood fiber and plastic resin. Most manufacturers blend 40 to 60 percent reclaimed wood or bamboo fiber with recycled polyethylene or polypropylene, which is why the products advertise recycled content and why they resist rot, splinters, and insect damage better than solid lumber. The plastic shields the fiber from moisture, and the fiber gives the board the stiffness a pure plastic board lacks.
Capped and Uncapped Boards
An uncapped board is one material from face to core. Color comes from pigments mixed through the entire board, and moisture can work into exposed fiber over time, which is why uncapped products fade and grow mildew in shaded corners. A capped board wraps the core in a solid polymer shell that carries the color and texture. The cap blocks moisture and staining, and most capped products carry 25- or 30-year warranties against fading and staining, while uncapped boards typically warrant 10 to 15 years.
Solid, Hollow, and Grooved Profiles
Profile choice affects weight, price, and installation:
- Solid boards weigh the most, feel closest to wood underfoot, and cost the most per foot.
- Hollow boards are lighter and cheaper, but the hollow core makes them noisier and less rigid, so joist spacing usually tightens to 12 inches.
- Grooved boards have channels milled into both edges to accept hidden fastener clips, and they can still be face screwed when the groove is not used.
Weight is a practical detail, not a footnote. A 12-foot 5/4 board weighs roughly 28 pounds, close to double a cedar board of the same size, and that weight shows up in freight costs and in how many boards one person can carry. Plan the delivery drop and the crew before the truck arrives.
Cutting and Fabricating Composite Boards
Composite boards cut with the same saws used for wood, but the plastic content changes blade selection and technique. The material dulls standard steel blades quickly and throws a fine dust that looks like flour. A carbide-tipped blade with 40 to 60 teeth makes clean cuts on deck boards, and a blade designed for aluminum or plastic works even better on the dense polymer surface. When you are cutting composite boards, run the saw at full speed and let the blade do the work; forcing the cut melts the plastic and leaves a ragged edge.
Cut Direction and Feed Speed
Cut with the finished side up so the blade exits through the back of the board, which puts any chip-out on the hidden side. On grooved boards, cut with the grooved side down when the groove sits near the cut line. Move the saw steadily without stopping; a stalled blade dwells in one spot and melts the polymer, and the burned edge will not match the rest of the deck.
Managing Dust and Heat
The fine dust from composite cutting carries the same health warnings as wood dust, so wear a dust mask and eye protection and cut outdoors or under a collector. Friction from cutting also heats the plastic. If the edge looks melted or the blade gums up, slow the feed rate, let the blade cool, and switch to a blade with more teeth and a higher hook angle. Saws with dust ports connected to a shop vacuum keep the work area clean and the cut line visible.
Composite vs. Wood and Other Decking Materials
The buying decision usually comes down to composite versus wood, with PVC and tropical hardwood as the outer options. Price, lifespan, and maintenance differ enough that the cheapest board per foot is rarely the cheapest board per year.
| Material | Material cost per sq ft | Typical lifespan | Maintenance | Notes |
|---|---|---|---|---|
| Pressure-treated pine | $2 to $4 | 10 to 15 years | Seal every 1 to 2 years | Cracks, splinters, and cups |
| Cedar | $3 to $6 | 10 to 15 years | Clean and seal yearly | Splits and fades in sun |
| Composite, capped | $5 to $9 | 25 to 30 years | Soap and water | Resists rot, mold, splinters |
| PVC | $6 to $10 | 25 to 30 years | Soap and water | Runs hot in direct sun |
| Tropical hardwood | $6 to $12 | 20 to 25 years | Oil every 1 to 2 years | Dense, rot resistant, costly |
Lifespan and Warranty Math
The price gap between pressure-treated pine and capped composite closes once maintenance is priced in. A treated deck needs sanding, sealing, and fastener checks every couple of years, and most treated boards show cracks and raised grain within five. A capped composite deck needs a hose and mild soap a few times a year. Homeowners who plan to stay more than a decade usually break even on composite within the first 10 years, and the savings compound after that.
Tropical Hardwoods as the Wood Alternative
Buyers who want real wood grain and can pay for it look at mahogany, meranti, and balau, the dense Southeast Asian and South American hardwoods sold as decking. These species rate naturally durable against rot and insects, and the durability of tropical hardwood decking depends on the species and grain density: balau is among the hardest, meranti sits in the middle, and all of them cost more per foot than cedar. They also need oiling to hold their color, and their weight makes them slower to install.
Cleaning, Repair, and Restoration
Composite resists the problems that kill wood decks, but it still collects pollen, leaf stains, and mildew in shaded corners. The right cleaning schedule is simple. Most manufacturers recommend a soft brush, warm water, and mild dish soap two to four times a year, and the routine takes four steps:
- Sweep the deck to lift leaves and grit that trap moisture.
- Wet the boards with a garden hose to loosen the surface film.
- Scrub with a soft brush and soapy water, working along the grain.
- Rinse thoroughly and let the boards dry before moving furniture back.
A pressure washer works on capped boards if the nozzle stays above 1,500 psi and the wand keeps moving, but a focused jet can etch the cap or lift the texture. Skip chlorine bleach on uncapped boards; it strips color and dries the fiber.
What the Warranty Actually Covers
Manufacturer warranties split into three layers: fade and stain coverage, structural coverage, and labor coverage. Fade and stain terms apply to capped boards and pay for replacement when color change passes a published threshold. Structural terms cover cracking, delamination, and breakage for the full term. Labor coverage is separate and shorter, often five years. Read the threshold language before buying, because a board that fades 10 percent in the shade may look fine to the eye and still sit inside the warranty.
When to Repair and When to Replace
Scratches on capped boards often brush out or fade with time, and mildew responds to cleaning. Cracked, delaminated, or badly faded boards need replacement, and the repair process borrows the steps used when restoring cracked, weathered decking: pull the damaged boards, check the joists and flashing underneath, and install the replacements with the same gaps and fastener spacing as the original run. Keep a few spare boards from the original order for color-matched repairs later.
Fastening Systems and Installation Sequence
Fastening is where composite decks win or lose their looks. Face screws are the fastest and cheapest method, but every screw head stays visible and every plug or cap can pop over time. Hidden fasteners hide the hardware entirely and create the clean, uninterrupted surface buyers associate with premium decks. The trade-off is cost: hidden fastener clips run roughly 50 cents to $1.50 per square foot, and they require a grooved board or a routed edge.
Hidden Fastener Systems Compared
Hidden systems fall into two families. Clip systems slide into the groove milled in a grooved board and screw to the joist, and the next board traps the clip and locks the gap. Track systems screw a metal strip to the joist first, then the board slides into the track. Both keep the surface clean, but they differ in expansion behavior: clips let the board move along its length, while some tracks restrict movement and force the board to expand against the fastener. The comparison between hidden decking fasteners usually comes down to gap control versus install speed.
Gap and Spacing Rules
Composite expands and contracts more than wood, so spacing rules matter. Leave a 1/8-inch gap between boards for drainage and expansion, 1/4 inch at the house wall and fascia, and follow the manufacturer’s joist spacing: 16 inches on center for most boards run at 90 degrees, 12 inches for diagonal or 45-degree runs. A board laid tight in summer can buckle in winter as it shrinks against the fasteners.
Face Screws and the Full Sequence
Face screwing still dominates budget decks because it needs no special boards and no clips. Countersunk screws with color-matched plugs take longer but cost less than clips, and flush-driven plugs hide the hardware well.
Installation order stays the same across methods: lay the framing and check it is square, run the boards with the crown up and the best face visible, fasten every joist crossing, and finish the ends with trim. Installers who want the clean look without grooved boards can turn to concealed screw-down hidden fastener systems that leave no visible head. Composite rewards planning at every step, from the blade you cut with to the clip you fasten with, and the decks that last 25 years are the ones where the details were decided before the first board went down.