High levels of crawl space humidity can cause many problems in Raleigh NC homes. During a home inspection, if signs of abnormal moisture are detected, the homeowner should make corrections to the home as soon as possible. This may require hiring a contractor who specializes in crawl space moisture control.
High moisture content in crawl spaces will eventually cause damage. Two different types of damage are typical. First, if the source of moisture is directed at a foundation wall, such as from a gutter, the foundation wall can suffer significant damage, such as sagging, cracking, warping, and deterioration. Two, high moisture content in a crawl space damages insulation, creates a perfect environment for fungal growth, allows termites to thrive, and can eventually cause wood to rot.
Let’s take a look at an example where a downspout contributed to a cracking foundation wall on a Raleigh NC home. The lot was slightly sloped from front to back and a downspout was pouring water at the front of the house, just to the right of center. The land in front of the house was flat, so water from the downspout collected here. The water not only pooled, it ran through the foundation wall, under the house and out the right rear.
When this house was inspected, it was only six years old, but the foundation wall on the right front, right middle, and right rear were cracked. Basically the right side of the house had fallen down. The crack in the right rear was about a half inch wide. This was an expensive repair that involved consultation with a structural engineer. The moral of the story here? The gutters are not enough; the homeowner must ensure downspouts direct water away from the home.
Now for the other issues: mold, termites, rotten wood, and damaged insulation. The insulation absorbs moisture, then becomes heavy, begins to deteriorate and ends up falling on the floor. Damp wood structural members are a perfect place for molds to flourish. These molds can enter the interior of the house since the air in the basement is exchanged with the indoor air (that is another topic for another time). And we all know that termites need moisture to survive, they love to consume wood, so damp wood is a playground for them.
Lastly, if high humidity levels continue for long periods of time, wood framing members can rot. During a recent home inspection, it was discovered that a half-inch screwdriver could easily be inserted into much of the frame. Repair costs were significant as additional bracing had to be added to support the weakened frame.
We could go deeper into each of these individual topics as the ramifications of a wet basement are significant. Also, crawl space drying, mold remediation, soil classification, etc. they can get very detailed. But for now, just remember to check out those gutter downspouts and their potential effect on your home life.
