Serving the Entire Treasure Valley and Beyond

Crawl SpaceJuly 20, 2025 7 min read

Why Boise Crawl Spaces Need Extra Care

Fully Licensed
Insured
DEQ Compliant

For decades, building codes required crawl spaces to have vents to 'let the moisture out.' In Boise, this old wisdom is actually destroying homes. Here is why our unique high-desert climate demands a different approach.

The 'Wet Feet, Dry Head' Problem

Boise has a unique problem: we live in a desert (dry air), but we flood our soil with irrigation water (wet ground). This creates a massive vapor pressure differential. The moisture in the damp soil wants to rise into the dry air of your crawl space and home. If you have open vents, you aren't airing out the crawl space; you're creating a chimney effect that pulls ground moisture up into your floor joists.

Why Vents Don't Work Here

In the summer, we bring hot, outside air into a cool crawl space. When hot air hits cool surfaces (like your AC ducts), it condenses. We see "raining" crawl spaces in July solely due to condensation from vents.

In the winter, those same vents let in sub-freezing air that freezes pipes and cold-soaks your floors, skyrocketing your heating bills.

The Irrigation Factor

When the canals turn on in April, the water table in many Boise neighborhoods rises by several feet. A standard vented crawl space does nothing to stop this rising dampness. The only barrier between that water and your subfloor is... air.

The Solution: Encapsulation

The modern building science standard is encapsulation. We seal the vents, insulate the walls (not the ceiling), and install a heavy-duty vapor barrier (typically 20-mil) that spans the entire floor and wraps up the walls/piers. We essentially turn your crawl space into a clean, dry, conditioned mini-basement. It stops mold, protects structure, and lowers energy bills by ~15%.

Stop the Water Damage.

Water issues don't get better with time—they get more expensive. Get a professional opinion before the next storm.

Check My Availability