Out of sight, out of mind — that's how most homeowners think about their crawl space. But this hidden area directly affects your floors' temperature, indoor air quality, moisture levels, and energy bills. Here's what you need to know.
Why Crawl Spaces Matter
Up to 40% of the air you breathe inside your home comes up from the crawl space through a phenomenon called the "stack effect." If your crawl space is damp, moldy, or poorly insulated, those problems affect your living space above.
Vented vs. Sealed Crawl Spaces
Traditional Vented (Older Approach)
Older building codes required crawl space vents to allow air circulation. The theory was that ventilation would prevent moisture problems. In practice, vented crawl spaces in humid climates often make moisture problems worse — warm, humid air enters and condenses on cooler surfaces.
Sealed/Encapsulated (Modern Best Practice)
Current building science recommends sealing the crawl space from outside air, installing a vapor barrier on the ground and walls, insulating the walls with closed-cell spray foam, and conditioning the space. This approach dramatically reduces moisture, improves comfort, and saves energy.
Insulation Options
- Closed-cell spray foam on walls: The premium option — insulates and creates a vapor barrier simultaneously. R-6.5 per inch.
- Rigid foam board on walls: Cost-effective alternative to spray foam. Installed with adhesive and sealed at seams.
- Floor insulation (batts): For vented crawl spaces — fiberglass or mineral wool between floor joists. Must be properly supported to prevent sagging.
- Spray foam on floor above: Seals and insulates the floor in one step. Excellent for vented crawl spaces.
Signs of Crawl Space Problems
- Cold floors in winter
- Musty odors in your home
- Visible mold or standing water in crawl space
- Sagging or fallen floor insulation
- High humidity levels indoors
- Pest activity (rodents, insects)
Don't ignore your crawl space. Schedule a free crawl space assessment and we'll evaluate your situation and recommend the right solution.