Composite Deck Building in Tacoma, WA

Composite deck building makes sense for a lot of Tacoma homeowners because the boards do not rot, splinter or need staining. With about 155 rainy days a year, a wood deck here needs regular cleaning and a new coat of finish every few years; a composite deck mostly needs a wash. What composite does not change is the framing underneath, which is almost always pressure-treated lumber. A composite deck lasts only as long as that frame, so the way we build the structure matters as much as which boards you pick.

Capped composite, uncapped composite and PVC

Most composite boards sold today are capped: a wood-plastic core wrapped in a harder polymer shell that resists stains, fading and moisture. Uncapped boards cost less but absorb more water and are more prone to mold and staining, which is a real issue in shady, damp yards. PVC boards contain no wood fiber at all, weigh less and handle moisture best, at a higher price. Forbes Home lists capped composite at about $30 to $60 per square foot installed, uncapped at $20 to $40 and PVC at $40 to $70.

The frame under the boards

Composite boards usually call for joists spaced closer together than wood decking, often 16 inches on center or less, and closer still for diagonal patterns. We use ground-contact rated lumber for posts and framing, put joist tape on the tops of joists so water cannot sit in the fastener holes, flash the ledger where it meets the house, and use hangers and screws rated for treated wood. Posts stand on concrete footings with standoff bases so their end grain stays out of standing water.

Algae and shade

Composite will not rot, but it is not immune to the Northwest. In shade and under firs, a green film of algae or mildew can grow on the surface, and needles and leaves trapped between boards hold moisture. Keeping board gaps clear, choosing a capped board and washing the deck once or twice a year with a cleaner the manufacturer approves keeps it looking right. Darker colors also show pollen and dust less than very light ones.

Heat, color and fading

Tacoma summers are mild, so the heat that can make dark composite uncomfortable in hotter climates is less of an issue here, but dark boards in full sun can still get warm in July and August. Capped boards resist fading better than older uncapped products. We bring samples to the estimate so you can see colors in your own light.

Hidden fasteners and board layout

Most capped composite boards are installed with hidden clip fasteners that sit in a groove along the board edge, leaving a clean surface with no screw heads. The clips also set a consistent gap for drainage. Picture-frame borders, where a row of boards runs around the edge, hide the cut ends and give a finished look. Composite expands and contracts with temperature more than wood does, so gaps at the ends of boards follow the manufacturer's instructions.

Manufacturer warranties

Composite brands back their boards with limited residential warranties; Trex, for example, states that its decking and railing carry limited residential warranties ranging from 25 to 50 years, depending on the product. Those warranties cover the boards, usually require installation to the manufacturer's instructions, and do not cover the wood framing underneath. We follow the installation guide for the product you choose.