Composite vs. Cedar Decking in the Pacific Northwest

A deck in the Pacific Northwest gets maybe ten good weekends a year and forty inches of rain the rest of the time. That reality — not the showroom sample — should drive the composite-versus-cedar decision. Here’s the honest comparison from crews who build both.

The PNW factor: rain, moss, and shade

Our climate is brutal on wood decking specifically. Constant moisture feeds rot and mold; canopy shade grows moss in the grain; and the freeze-thaw and UV cycle checks and greys the surface. A material’s PNW performance is mostly about how it handles being wet for months. That’s the lens.

Capped composite: the PNW default

Capped composite (Trex, TimberTech, and similar) is a wood-plastic core wrapped in a protective polymer shell:

• No staining or sealing, ever. The single biggest advantage here — you reclaim the every-other-summer maintenance weekend that cedar demands.
• No moss farming. The capped surface doesn’t hold moss in grain the way wood does; a rinse handles it.
• No splinters, no rot, no checking. It stays what it was on day one.
• Cost: $60–$110 per square foot built right — most projects $18,000–$45,000 with railings and stairs.

The tradeoff is upfront cost and a slightly less “natural” feel than real wood (though modern composites have closed that gap dramatically).

Cedar: real wood, real maintenance

Cedar is beautiful and naturally rot-resistant, and it costs 20–30% less upfront than composite. But in our climate:

• It needs staining/sealing every other year to fight moisture and UV — miss it and the wood greys, checks, and starts to degrade.
• It grows moss in shaded, grained areas and needs regular cleaning.
• It ages faster here than in drier climates, even maintained.

Cedar makes sense if the budget is tight, you genuinely enjoy the maintenance ritual, or the natural-wood look is non-negotiable for the home. Eyes open about year eight.

The lifetime math

Cedar’s lower entry price is real, but add up eight years of stain, sealer, cleaning, and your weekends, and composite’s premium usually pays back — while looking better the whole time. For a deck you’ll keep long-term, composite is typically the smarter dollar. For a short-term or budget build, cedar is defensible.

What matters under both

Neither material saves a deck built on a bad frame. The parts that actually fail — and cause the collapses you read about — are the footings below frost line and the flashed, bolted ledger where the deck attaches to the house. We build the structure right first, hidden fasteners standard, then let you choose the surface. Here’s our deck approach.

Planning a deck? Book a free estimate — we’ll price both materials honestly against your yard and budget. See custom decks.