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wet crawl space insulation

Wet Insulation

Insulation is an important system for any healthy home, as it regulates temperatures throughout the structure. When moisture gets into your crawl space, the insulation can get wet and damaged in the process.

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Every healthy home depends on insulation to maintain energy efficiency around your home, and to control temperature around your home. In homes with a crawl space foundation, insulation is often located below the home. Crawl spaces are susceptible to water damage from many different sources, each of which can also lead to wet insulation – a problem for your entire home. Tar Heel Basement Systems has crawl space solutions that keep your entire crawl space dry, including your insulation. 

What Causes Wet Insulation?

Wet insulation is a direct cause of moisture in your crawl space. Here are the most common ways that water gets into this vital area below your home and disturbs the functionality of your crawl space insulation. 

Open Crawl Space Vents

Most crawl spaces have open vents along their foundation walls. In the past, crawl spaces were designed with these vents as a means to allow humidity to escape from the crawl space. However, homeowners have come to find out that these open vents allow the opposite to happen. During the particularly muggy summers in North Carolina, humidity from the outside makes its way below your home. Essentially, open crawl space vents force your crawl space to emulate the environment outside. You can see how this causes your insulation to get wet during rainy days or hot summers. 

Humidity in Crawl Space

As mentioned, humidity can get into your crawl space through open vents, but there are a few other ways that humidity rises below your home. One such instance is when groundwater drains into the soil directly below your crawl space. Eventually, this water has to evaporate. When it does, the water vapor gets trapped inside your crawl space and causes condensation to form on every surface below your home – including the insulation. When water droplets form on the fiberglass insulation, it can have all kinds of negative effects such as inadequate temperature control or collapsed sections of insulation. 

The Stack Effect

You’ve probably heard the law of thermodynamics that states “warm air always rises”. Well, this happens in buildings all the time, and is referred to as the stack effect. Essentially, as warm air rises through your home, it will spread into every room on every level of your house, whether it’s one story or three stories. Eventually, the warm air escapes through your attic, but during its journey, it can have negative side effects on insulation and your larger air system. The stack effect starts in your crawl space, where humidity heats up the air below your home. As it rises through the floor boards, it permeates the insulation and causes it to get wet. 

Wet Insulation


Wet insulation is pretty easy to identify. First of all, look for visible water droplets on the surface of the insulation. Obviously, this is a clear indication that it is wet. However, sometimes the moisture seeps into the insulation material. When this happens, you might notice sagging or collapsed sections of damp insulation hanging from the top of your crawl space. Also, look out for any sections of insulation that might be on the ground of your crawl space. Moisture makes the insulation heavier, so this is a likely sign that the insulation is wet. 

It definitely could. Mold is almost synonymous with moisture, and this harmful fungus just needs humidity and organic material to thrive. Since crawl spaces often provide these conditions, mold easily grows on or around your wet insulation. This can become a major problem for you and your family because mold spores are dangerous to human health. Mold spores could spread into your home and cause respiratory issues or grow in other places such as bathrooms or closets. Make sure when looking out for wet insulation that you wear protective gear in case of mold and mildew. 

Call a professional. While handy homeowners might be willing to remove wet insulation, we don’t recommend anyone try this on their own with a DIY project. Pretty much any type of insulation is made with fiberglass, a material that can cause problems for your skin or eyes if it comes into contact with them. Without the proper protective gear, you’ll be putting your health at risk. Moreover, crawl spaces are tricky to work in. We have trained professionals that know how to traverse this tight area with skill. Your crawl space could become more damaged with even the slightest wrong move. We care about your safety, so when it comes to removing wet insulation, we recommend contacting a professional service like Tar Heel. 

Call Tar Heel for a Free Inspection

Since 2003, Tar Heel Basement Systems has been providing crawl space repair for homeowners across the state of North Carolina in Northern North Carolina, the Raleigh/Durham/Chapel Hill metro area, Wilmington, and the Winston-Salem/Greensboro/High Point metro area. With thousands of positive online reviews and recent awards from Home Advisor and the Better Business Bureau, our commitment to honest and quality business is clear. Don’t let crawl space problem signs destroy your home’s insulation. Contact us today to schedule a free inspection and experience the benefits of our crawl space solutions! 

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Our Service Areas

Greensboro Location

611 Summit Ave, Suite 5
Greensboro, NC 27405

Raleigh/Durham/Chapel Hill Location

3333 Air Park Road
Fuquay-Varina, NC 27526


1209 Culbreth Dr., Ste 205
Wilmington, NC 28405

Winston-Salem/High Point Location

2910 Griffith Rd
Winston-Salem, NC 27103