Composite vs. wood decking: a Seattle homeowner's guide

The quick answer

If you want a deck you mostly just rinse, and you plan to stay in the house a while, composite is usually the better fit for Seattle's climate. If you love real wood, want the lowest starting cost, or don't mind a regular weekend of maintenance, wood remains a good, honest choice.

Neither is wrong. The rest of this guide explains why, so the choice matches how you actually live.

Side-by-side table

Composite vs. wood: the full comparison

Consideration	Composite	Wood (cedar / treated)
Upfront cost	Generally higher for materials	Generally lower to start
Cost over time	Little ongoing spending on finishes	Recurring cleaning and staining costs or time
Routine upkeep	Washing a couple of times a year	Cleaning plus periodic sealing or staining
Wet-climate behavior	Capped surface resists moisture and rot	Needs a good finish and airflow to hold up
Moss & mildew	Surface film usually washes off	Can work into the grain if left
Look and feel	Consistent color, many wood-grain patterns	Natural grain that weathers over time
Splinters	Not a concern for bare feet	Possible as boards age
Heat in direct sun	Darker colors can get warm; lighter ones help	Usually stays a bit cooler
Scratches & dents	Cap resists them, but deep scratches can't be sanded out	Softer woods dent, but can be sanded and refinished
Framing underneath	Pressure-treated wood	Pressure-treated wood

Performance varies by manufacturer and product line. We compare specific boards during the estimate.

Cost over time

Composite boards typically cost more to buy than cedar or pressure-treated decking. That's the number most people compare first, and it's only part of the picture.

A wood deck comes with recurring costs: cleaners, stain or sealer, and either your weekends or a paid crew to apply them every few seasons. Boards that crack or rot need replacing along the way. Composite shifts more of the spending to day one and less to the years after.

Which ends up costing less overall depends on how long you'll own the home, how much of the upkeep you'd do yourself, and how exposed the deck is. We're happy to talk through both scenarios with real quotes for your project rather than rules of thumb.

Look & feel

Wood has natural variation: knots, grain and color that change as it weathers. Some people love that, and some find the greying frustrating. Modern capped composite imitates wood grain convincingly and holds a consistent color, though up close it still reads as a manufactured product.

Underfoot, capped composite feels dense and solid, PVC a bit lighter, and cedar softer and warmer. Bringing samples outside and standing on them in your own light is the best test.

Heat & comfort

On hot, sunny afternoons, dark composite can get noticeably warm to bare feet. Lighter colors, heat-reflective product lines, shade from a pergola or tree, and PVC boards all reduce that. Wood generally stays a little cooler.

In Seattle this matters mainly on south- and west-facing decks during summer. On a shaded deck under firs, heat is rarely the issue; damp is.

Upkeep by season

Composite

• Spring: wash with soap and a soft brush; clear the gaps between boards.
• Summer: wipe up grease and spills promptly; use a grill mat.
• Fall: sweep leaves and needles often so they don't sit and stain.
• Winter: plastic shovel only; skip rock salt unless the maker allows it.

Wood

• Spring: clean, check for raised screws, soft spots and splits.
• Summer: re-stain or seal when the finish starts to wear, on a dry stretch.
• Fall: remove debris and trim plants back so boards can dry.
• Winter: watch for moss and slippery algae on shaded areas.

Framing is wood either way

This surprises many homeowners: a composite deck still sits on a wood frame, usually pressure-treated lumber. The boards may never rot, but joists, beams and the ledger at the house can if water is allowed to sit.

That's why flashing at the house, protective joist tape, correct joist spacing and airflow underneath matter just as much on a composite deck. When comparing estimates, ask how each builder handles the frame, not just which boards they'll use.

Permits overview

Material choice rarely changes whether you need a permit; design does. Height above grade, size, attachment to the house and location can all come into play. In Seattle, decks and fences fall under the Seattle Department of Construction and Inspections (SDCI). Elsewhere in the county, King County or your city's building department sets the rules.

How to choose

Still on the fence? Read more about our composite decks and cedar and pressure-treated decks, or book a free estimate and we'll bring samples of both.