Vented vs. Encapsulated Crawl Space: Which Is Right for Spokane?
For decades, builders vented crawl spaces on purpose — the idea was that outside air would dry them out. In a climate like Spokane's, that logic often backfires. Here's the honest comparison.
The old approach: vented
A vented crawl space has open vents around the foundation meant to let air circulate. The problem: in humid summer months, warm outside air condenses on cooler surfaces under the house, adding moisture; in winter, those same vents pour freezing air under your floors. The result is often the opposite of dry.
The modern approach: encapsulated
Encapsulation seals the space off entirely — a heavy-duty vapor barrier over the floor and walls, closed vents, and a dehumidifier to control humidity. The crawl space becomes a clean, dry, semi-conditioned part of the house instead of a damp hole under it.
Side by side
| Vented | Encapsulated | |
|---|---|---|
| Ground & humid-air moisture | Gets in freely | Sealed out |
| Mold & wood rot risk | Higher | Much lower |
| Winter floor temperature | Cold | Warmer |
| Heating efficiency | Worse | Better |
| Up-front cost | None (existing) | $5,000–$15,000 |
Why encapsulation usually wins in Spokane
Cold winters, snowmelt, and humid summers are exactly the conditions where venting causes more moisture problems than it solves. Encapsulation costs money up front, but it's typically far less than the framing repair, mold remediation, and floor replacement that chronic crawl space moisture eventually forces.