Case Studies

The Drying Co./ThermalTec Case Studies: Crawl Space Encapsulation in Midlothian

Tuesday, July 9th, 2019 by Erin Dougherty


This home had an encapsulated crawl space installed when it was constructed. This is still a relatively new home, but the encapsulation didn’t have the desired effect. Initially, the crawl space was encapsulated with a 6-mil vapor barrier and R-11 vinyl faced fiberglass insulation. The homeowner contacted us with concerns about an ammonia, or animal urine odor in her home and poor air sealing.

Upon the completion of a thorough inspection, we found that moisture had penetrated the porous cinder block foundation wall and saturated the R-11 vinyl faced fiberglass insulation on the crawl space walls. In addition, the crawl space had a high relative humidity, moisture was making it into the crawl space and becoming trapped. This resulted in the fiberglass insulation emitting an animal urine and ammonia odor that the homeowner was complaining about. 


Our goal was to remedy the Home Owner’s concerns of foul odors in her home and wasted energy. To achieve this, we installed a 20 mil Clean Space Vapor Barrier on the floor of the crawl space and around the piers. We installed Foamax board insulation on the walls leaving a 3-inch viewing strip for pest control companies to do their inspection. We applied spray foam insulation to the rim and band and sill plate to create an air seal and reduce drafts coming into the crawl space. Finally, we installed a Sani Dry Sedona Dehumidifier, the leading dehumidifier on the market, to pull any moisture that enters the crawl space out.

This approach, compared to the initial encapsulation approach, will reduce the amount of moisture and outside air that enters the crawl space. By doing this, we are creating as much of an airtight seal in the crawl space as possible to keep groundwater and humidity out of the crawl space. The addition of the Dehumidifier addresses any moisture that may enter the crawl space and controls relative humidity, which coupled with warm temperatures and organic material can result in mold and mildew in the crawl space. This solution keeps the homeowner from experiencing any more foul odors in their home and makes the home more energy efficient.  

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Our Locations:

The Drying Co./ThermalTec
236 Industrial Blvd
Suite A
Toano, VA 23168

The Drying Co./ThermalTec
Mailing Address
P.O. Box 637
Toano, VA 23168
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