RTS Environmental Services, Inc.

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Licensed, Insured, and Accredited · Residential and Commercial

30 Years Experience · Family Owned & Operated

Crawl Space Conditioning

Crawl Spaces are often subject to humidity and damp or wet conditions which will grow mold and cause strong odors. These conditions can also cause wood rot and structural changes over time.  The following are treatments which are important to consider to improve a crawl space:

Vapor Barrier-  Earthen floor crawl spaces must be covered with a thicker membrane (12 to 20 mil reinforced poly is typical). This membrane should be at a minimum covering the floor with sealed and overlapped seams. An encapsulating vapor barrier can be installed on walls and structural columns as well. If there are passive vents to your crawl space they should be covered and sealed to disallow outdoor air from entering.

Insulation– Often paper backed fiberglass is used and is installed upside down causing mold growth on the paper. In this case and where fiberglass has been subject to high moisture it is removed and disposed and replaced with a foil backed version properly effaced to the subfloor areas.  A thermal rating of R-19 or better is best when replacing insulation.
Insulating blankets on the walls is also a consideration (vinyl backing is best) and is installed with power driven fasteners to hold it in place. Expanding foam is also an increasingly popular insulating system.  Although this choice is more expensive this material is moisture resistant and fully minimizes air movement especially at the band boards and rim joist areas of crawl spaces.

Mold Treatments and Anti-fungal sealants–  Mold is the number one problem with crawl spaces.  The removal and remediation of mold is performed as follows. In many cases any old and moldy insulation and vapor barrier is removed. Cleaning the sub-floor and joists with an anti-fungal agent is performed to remove mold in an abrasive method. The application of an anti-fungal sealant is applied to the sub-floor and joists which inhibits mold.

Crawl Space Dehumidifiers- The dehumidification of crawl spaces is now a must have scenario to maintain humidity at or below 50%. In some cases larger more substantial size units are used in crawl spaces because of the rigorous conditions and high humidity.  Most will need to operate all year around. Smaller units can be used but don’t expect them to last more than a few years because they tend to operate continuously. If there are passive vents to your crawl space they should be covered and sealed to disallow outdoor air from entering.

Sump-pits-  Water entry is often an issue when foundation water enters low to the footers and walls which are below grade. A sump-pit with an ejection water pump will collect below grade water and pump it out doors away from the foundation.