WSDOT Facility Building Crawl Space Encapsulation – Deming, WA

The Washington State Department of Transportation (WSDOT) contacted us because they knew they had water coming in through their foundation vents from the snow. During our comprehensive inspection of the crawl space in the facility building, our estimator uncovered several underlying issues:

• Insufficient floor insulation
• Leak
• Higher moisture levels
• Damaged existing sump pump
• Heavy rodent damage.

Northwest Crawl Space Services (NWCS) completed the crawl space restoration in about three days, starting with a crawl space cleaning and then replacing the existing crawl space insulation. To address the leak, we replaced the existing sump pump and installed a new one. We also installed a dehumidifier and encapsulated the crawl space to maintain a dry, healthy environment and prevent future moisture issues.

Crawl Space Services Performed

• Crawl Space Clean and Sanitize: Removed old insulation, vapor barrier, animal feces, nests, carcasses, and debris. Sanitized with a disinfecting mold inhibitor.
• Crawl Space Rodent Exclusion: Sealed all entry points using concrete, steel wire, construction adhesive, and re-screened vents.
• Crawl Space Prescriptive Air Seal: Sealed all air gaps around plumbing, ducting, and electrical wiring penetrations with foam.
• Rim Joist Air Seal and Insulation: Installed R-10 rigid foam board cut to fit at all rim joist areas and seal perimeter gaps with spray foam for a continuous air seal.
• Vapor Barrier Installation: Installed 20-mil white Dura-Skrim® plastic vapor barrier secured with deep ground stakes and sealed with industry-standard tape.
• Crawl Space Insulation: Wrapped water supply lines and installed R30 fiberglass batt insulation in the subfloor.
• Dyer Vent Duct and Louvered Cap Installation: We installed the dryer vent duct through the crawlspace and terminated it with a louvered vent cap on the exterior siding.
• Dehumidifier Installation with Encapsulation: Installed a professional-grade AprilAire® dehumidifier with a built-in pump and a drain line to channel water away.
• Sump Pump System Installation (10-Year Warranty):
  • Preparation: Protected work area and removed standing water.
  • Catch Basin Setup: Installed a perforated backfill basin with lava rock filtration.
  • Sump Pump Installation: Installed a cast-iron sump pump with a flood alarm system.
  • Water Discharge: Directed water away from the house using a solid PVC pipe.