Sealing Up a Williamsburg, VA Crawl Space
Challenge
This homeowner in Williamsburg, VA was concerned about many issues within their crawl space. We sent out one of our experienced Home Performance Advisors to evaluate the situation and provide a quote to help rectify many of the homeowner's concerns. The first thing our advisor noticed upon entering the crawl space, was that the fiberglass insulation was hanging down from the floor joists. This insulation will absorb excess moisture like a sponge until it becomes too heavy, eventually falling out of the floor joists in wet chunks. The entire crawl space dirt floor was littered with debris and insulation pieces, and many areas of the existing vapor barrier were torn, exposing the dirt floor. The earth's moisture can rise through these gaps and raise the crawl space's relative humidity, which leads to other problems such as mold and mildew remediation.
Our advisor discovered that there was indeed mold growth forming on many of the wooden floor joists. Mold can grow on any organic material within the crawl space, so long as the relative humidity is above 55% during warmer temperatures. The mold spores can then rise into the home above and affect those with allergies or asthma. The homeowner made it quite evident to the advisor that he wanted us to remediate the growth and help prevent it from reoccurring.
The next thing our advisor noticed, was that there was efflorescence on the foundation walls. This occurs when moisture seeps through the porous cinderblock walls, bringing the inner sediments to the surface, and creating "chalky" marks upon the wall. This is a clear indication of water intrusion, which can explain the high relative humidity of the crawl space. It is also important to note that the foundation walls were lined with open vents. These vents allow the outside air and moisture to flow freely into the crawl space and affect the environment underneath the home, while also increasing the relative humidity.
Our advisor proposed a quote to the homeowner to help correct these issues and protect the crawl space from the outside air and moisture, and our team of installers was scheduled to install the products and services.
Solution
The first thing that we focused on doing was removing the debris and old fiberglass insulation batts from the crawl space. The wooden floor joists, riddled with mold growth, were sprayed using an antimicrobial called Shockwave. This solution kills the mold spores but does not remove any remaining staining. The mold can also grow back if the relative humidity and temperature of the crawl space are not controlled.
Once the floor joists were sprayed down with Shockwave, we installed a new vapor barrier over the dirt floor of the crawl space. Our installers used a 10-mil liner called CleanSpace Light. The CleanSpace is wrapped around every pier, and mechanically fastened up the foundation wall about six to eight inches above outside grade. This CleanSpace Light will help protect the environment from moisture rising from the earth and offers a clean and bright aesthetic.
The next step was to move the insulation from the floor joists to the foundation walls. We started by blocking the open vents from allowing outside air and moisture to get inside. Precisely-cut foam board pieces were cut to fit inside each vent, then sealed with can foam. We then covered the walls in a 1.5-inch-thick layer of spray foam. This insulation offers a value of R-10 and acts as a vapor retarder and moisture barrier.
The last product we installed was a SaniDry Sedona, an energy-efficient dehumidifier. This specialized unit will not only help to control the relative humidity of the crawl space but it will also circulate dry air around the area. Any moisture collected is then distributed to a condensation pump, directing the water out of the crawl space and away from the foundation via a hose line. A hygrometer is installed near the dehumidifier to help the homeowner monitor the relative humidity and temperature of the crawl space at all times.
With these solutions put in place, the homeowner can rest easy knowing that the crawl space is better protected from any outside influence. If you or someone you know is having moisture or mold issues within the crawl space, then give us a call to schedule your free estimate. We'll help you to keep the outside, outside!
