Composite Deck Cost in Washington
A Composite deck in Washington costs $45-$122/sqft installed with the state's 1.28× labor multiplier (West). Generic composite covers the entire wood-plastic-composite + capped composite + PVC market — Trex, TimberTech, Fiberon, Deckorators, MoistureShield, Wolf, Zuri, NewTechWood, DuraLife. Average 25-yr lifespan + no maintenance is the value vs PT pine which needs annual staining. Washington labor 1.28× national. Pacific Northwest rain + moss — composite recommended over PT.
Composite cost by deck size in Washington
Mid-tier Composite (TimberTech Pro Legacy) at Washington's 1.28× labor multiplier — ~$74/sqft installed.
Cost ranges include materials + labor + standard railing. Excludes permit ($290 baseline + 1.2% of project value), demolition (if replacing), and footings for 18″ frost depth.
Composite product lines in Washington
Composite installed cost ranges from $35/sqft (entry tier like Trex Enhance Basics) to $95/sqft (luxury PVC like AZEK Harvest). National median is $50-58/sqft for a mid-tier 2026-Q1 build — multiply by your state labor multiplier for local pricing.
Washington-specific notes
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FAQ — Composite in Washington
How much does a Composite deck cost in Washington?▾
In Washington, Composite decking costs $45-$122/sqft installed (national $35-$95/sqft × Washington's 1.28× labor multiplier). A typical 16×20 (320 sqft) Composite deck lands around $26,560. Mid-tier TimberTech Pro Legacy runs about $23,680 for the same scope.
Which Composite line is best for Washington's climate?▾
Washington's Pacific Northwest rain favors capped composite or PVC over PT pine — better moisture resistance. Fiberon Sanctuary performs well in this environment with proper drainage gap (1/8″-3/16″ side-to-side).
What's the permit fee for a Composite deck in Washington?▾
Washington permit fees typically run $218-$537 depending on jurisdiction and project value — most calculators use max(regional baseline $290, 1.2% of project value). WA permits $250-400. Seattle moss + rain notes.
How deep do footings need to be for a Composite deck in Washington?▾
Washington's frost depth is approximately 18″. Composite doesn't change the footing requirement — that's IRC R403.1.4-driven by frost line. Use Sonotube 10″ for typical loads. Verify with your local building department since AHJs sometimes require deeper depths than the state-published value.
Is Composite worth the money in Washington?▾
Composite vs PT pine over 25 years in Washington: PT pine = ~$38/sqft installed + ~$3/sqft/yr maintenance (stain/seal annually) = $118/sqft total. Composite mid-tier = $74/sqft installed + $0 maintenance = $74/sqft total. Composite typically wins the 25-yr TCO comparison by 20-40%, plus better resale value.
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