If your crawl space initially was constructed with fiberglass insulation, at some point, that insulation is going to sag. It’s not just a matter of gravity or deterioration with age. Fiberglass insulation is like a towel — just waiting to absorb water. Between gravity and moisture, it’s probable that the fiberglass insulation in your crawl space will sag, if it hasn’t already.

Moisture Causes

Other than the air’s humidity, how does moisture reach crawl space insulation? The answer lies with your foundation. If your home’s foundation is not waterproof, the water creeping in can sit in the concrete that touches the crawl space insulation. The water is trapped against the insulation, which absorbs it, becoming soggy and eventually sagging from the water weight and breakdown of materials.

Poor air circulation also traps moisture in the air in the crawl space, which affects the integrity of the insulation. Even if the insulation is not sagging, if the area is wet, it reduces the insulation’s effectiveness.

Foundation Repairs

It’s not enough to just replace sagging insulation. You need to find and address the moisture source before doing anything else. Hire a professional to look at your foundation to determine if there are any waterproofing issues such as cracks or water stains. Moisture trapped by insulation also may affect nearby wood such as your home’s framing.

If there are no visible issues, assess the slope/grading of your property as well as your gutters. Does the dirt around the foundation slope away from the house? If not, that may be the problem, as water from rain and snow is not flowing away from the foundation and sits against the concrete, pressing into it.

If you don’t have gutters on your home, you should install gutters because any water dripping off the roof will slide right down to be absorbed by the soil next to the foundation. For homeowners who already have gutters, make sure you maintain them. Regularly clear them out or install gutter covers. Downspouts should empty several feet from the foundation. Home improvement stores sell downspout extensions.

Replacing Insulation

Whoever constructed your home may have started with fiberglass, but you should not finish with it. It really is a poor choice for a crawl space. Do not remove fiberglass insulation unless you have experience; touching it with bare hands or breathing in pieces of it can be hazardous to your health.

A better option for crawl space insulation is rigid foam board. After the crawl space is sealed or encapsulated, a professional will install foam board insulation. This type of insulation won’t suck in water and sag from water weight. Spray foam also is an option.

Leaving sagging insulation as-is is not an option. If you don’t do anything, you create a bed of moisture in which mold will thrive, which can create health problems if it gets into the house via the framing, ductwork, or any other small opening you might not be able to see with the naked eye.

Acculevel Repairs Crawl Spaces

Acculevel offers full services for crawl space repairs. We address waterproofing problems and offer a free estimate for what needs to be done. Our mold remediation experts are certified, so you don’t have to worry about mold spreading when we remove it from your crawl space or basement. We repair cracks and can even shore up your foundation if it has shifted from water pressure or shifting soil underneath. If you live in the Midwest and your crawl space has moisture problems, contact us at (866) 669-3349 or email us at [email protected].