6 Common Crawl Space Problems

With such a warm, humid climate in the spring and summer months, humidity becoming trapped in the crawl space is a common problem many homeowners face.  Some of the most common things we see in crawl spaces in the Greater Richmond, Williamsburg, and Virginia Beach areas include.

1.       Mold & mildew growth on floor joists

2.       Falling/Fallen fiberglass insulation

3.       Missing, damaged, and crumpled vapor barriers

4.       Mold & mildew growth on the paper backing of fiberglass insulation.

5.       Efflorescence on foundation walls

6.       Insects and critters

Leaving your crawl space vents open in the summer doesn’t do the job of keeping the space dry. Instead, it allows hot humid air to become trapped and raises the relative humidity in the space. To learn more about the science behind this, watch this video “Why Vented Crawl Spaces Just Don’t Work”

Mold and mildew grow on floor joists as the relative humidity rises and warm temperatures are sustained. All mold needs to grow is a relative humidity above 60%, an organic food source (the wood substructure of your home), and warm temperatures. Mold and mildew growth on the paper back of fiberglass insulation is very common. Mold loves organic material, and it especially loves paper.  

Falling or fallen fiberglass insulation is a result of the material absorbing the moisture in the crawl space. It becomes heavy and with the help of gravity, begins to fall away from the floor. Often you may see that the insulation looks like it is “dripping” this is a process called delamination. Delamination occurs when the fibers in the insulation begin to separate from one another as a result of the moisture it’s holding.

We typically see missing, damaged, or crumpled vapor barriers in crawl spaces, this is because the vapor barrier installed at construction is a 6-mil thickness that is either simply laid on the ground or tacked into place with U-shaped stakes. The purpose of a vapor barrier is to prevent water vapor from the earth from rising into the crawl space and impacting the substructure of the home. However, if your liner is not sealed or has had holes put in to “keep it in place” it’s not going to do a very good job at keeping vapor out, in fact, it’s going to let it in. 6-mil vapor barriers are very thin, think of a standard trash bag, so they are easily damaged and displaced by service persons going in your crawl space or by critters running through or making a home down there.

Efflorescence on foundation walls occurs as moisture moves through porous foundation walls into the crawl space. As it moves through the wall it brings the minerals and sediment in the block with it. This results in a white powdery substance often described as looking chalky on the surface of the block. Efflorescence is a sign of moisture moving through the foundation wall and into the crawl space adding to the relative humidity. When looking for bulk water intrusion, we’ll often notice things such as water staining on the walls, erosion of soil around the foundation wall where the water is entering, and the ground being softer in those areas.

The dark, damp environment of your crawl space makes a great home for insects and critters. Our inspectors often find that mice have nested in fiberglass to keep warm, snakes have made a home and shed their skin in the crawl space, and crockets, spiders, and a number of other insects find the safety of the damp, dark crawl space, the perfect place for them to call home.

How do you know if you have any of these problems in your crawl space? The sure way is to have a professional inspect your crawl space. Our Home Performance Advisors do thorough inspections and take photos of their findings to give you a complete look at what’s happening in your home.

You can also check out our article “10 Signs You May Have Crawl Space Problems” to see if you have any of these symptoms without going in your crawl space. You could still have moisture problems in your crawl space and not notice these 10 Signs, it’s always best to get a professional to look at your home so you can have the peace of mind knowing what’s going on.

For a free crawl space evaluation, call The Drying Company at 1-757-566-8622 or 1-757-566-8622.