Ask House Spouse · Exterior & Weatherproofing · Decks & Outdoor Structures
How often should a deck be stained or sealed in the PNW?
Short answer
Semi-transparent stain lasts 2–3 years on a PNW deck; solid stain lasts 4–6 years; clear sealer lasts 12–18 months. Whichever you use, plan on a full clean and re-coat schedule and stick to it — a deck that's gone gray from neglect needs more than a re-coat, it needs board replacements first.
What kills PNW decks
Moss, standing water, and UV — in that order. Horizontal boards catch and hold moisture; south-facing exposures burn the finish; north-facing exposures grow moss. Cleaning matters more than the stain brand.
The right sequence
1) Clean with a dedicated deck cleaner (not just pressure wash — that furs the wood). 2) Neutralize with a brightener. 3) Let it dry 48 hours. 4) Sand any raised grain. 5) Stain. Skipping steps 1–2 is why re-stains fail in a year.
When to replace boards first
Screwdriver test again: any board that dents needs replacement before restaining. Deck boards are $3–$8 per linear foot for pressure-treated, more for cedar or composite. Handyman scope for straight replacement; larger structural repairs (joists, ledgers) sometimes call for a contractor.
What we see on Home Health Assessments
Around 74% of PNW roofs we assess show active moss establishment — accelerates shingle wear by an estimated 3–5 years if untreated.
Caught early on assessment: $220–$650 · Left until failure: $3,500–$22,000
Based on real experience across Snohomish and King County, exterior & weatherproofing issues like this are among the ones homeowners most often miss until they become expensive. Our Home Health Assessment catches them early — while they're still a maintenance item, not a repair.
How the Home Health Assessment worksServices we'd bring to this job
Related questions
Exterior & Weatherproofing · Siding & Exterior Paint
How do I know if I have wood rot in my siding or trim?
Take a screwdriver and press firmly (not hard) against suspect wood — mainly the bottom edge of trim, corner boards, and any spot with peeling paint. Sound wood resists; rotten wood dents or crumbles. In the PNW, rot almost always starts at horizontal surfaces or trim-to-siding joints where water sits.
PNW Seasonal · Spring Cleanup
How do I remove moss from my roof safely in the PNW?
Don't pressure-wash a shingle roof — you'll shorten its life dramatically. Instead, apply a zinc-sulfate-based moss killer in dry weather, let it work for 1–3 weeks, then gently brush loose moss off with a soft roof broom or leaf blower. Install zinc strips along the ridge for long-term prevention.