Most of the homes in Cary, North Carolina are built with crawl spaces. Since the summer climate here in Cary is hot and humid and rain is frequent (some summers), crawl spaces are very susceptible to moisture. In addition, the soil in Preston area of Cary contains a lot of clay which tends to retain moisture.
Mold and Mildew can contaminate the crawl space
When the air in a crawl space is humid for extended periods, all kinds of problems can occur. Mold and mildew can grow on the insulation and floor joists which can contaminate the crawl space air and be drawn into the home. Excess moisture can cause wood rot and foundation issues.
This is an issue Lenda and I are currently experiencing as we rebuild the Cary ranch home we recently purchased in Preston. We are installing custom hardwood flooring throughout the home and our flooring contractor measured the moisture in our sub floor.
He determined that we could not install the floor until the moisture level was reduced, otherwise buckling or warping is likely to occur.
Solution – a perimeter drainage system
Our solution is to install a drainage system which prevents water from penetrating the crawl space. Our contractor is John Walke of Triangle Waterproofing for these repairs. John has been in the business since 1974 and several of our Real Estate clients have used his company with excellent results.
John’s first step in installing a system is to have his crew dig a perimeter trench down to the footing level (about 12 inches in our case) on the interior wall of the foundation. A perforated pipe wrapped in filter cloth is laid in the bottom of the trench and the trench is then filled with stone. The system drains the collected water to the lowest corner of the crawl space and then out through the foundation wall and away from the house. In some cases where the fall or grade is not sufficient to direct the water, a sump pump is installed.
Vapor Barrier and De- Humidifier
After the waterproofing drain system is in place, a vapor barrier is installed on the crawl space ground to prevent soil moisture from migrating into the crawl space. Next a de-humidifier designed specifically for crawl spaces is installed which runs during the more humid months of the year.
Here is what John says to look for as you investigate your crawl space:
Standing water in the crawl space, standing water on the top of the vapor barrier, or water stains on the vapor barrier.
A moist vapor barrier or soft ground underneath it.
Moisture in the sub floor insulation.
Hopefully you will find floor joists that are dry and free of mold. If your investigation turns up any of the above markers, a professional water proofing company should be called in for further analysis.
In our case we simply have to wait about three weeks until the crawl space dries out before we can safely install our new hardwood floor.