Your crawl space probably isn’t something you think about that often. However, your crawl space has critical insulation that plays an important role in protecting your home. If you have a newer home — between 10-15 years old — you probably don’t need to think about replacing your crawl space insulation. 

However, if you live in an older home, you may want to think about calling in a professional to have your crawl space insulation replaced. On average, crawl space insulation lasts 20 to 40 years under decent conditions. If you live in a particularly humid climate, you may need to replace it in as little as ten years. 

Factors that Impact Crawl Space Insulation Replacement

Some homeowners need to check on their crawl space insulation every decade, while others can go more than 40 years without needing replacement. Several factors impact how often you’ll need to swap out your crawl space insulation.


Moisture can wreak havoc on many parts of your home, and insulation is no exception. If your insulation is exposed to excess moisture, it can become damaged and less effective. Worse, moisture tends to stay in insulation and can lead to mold growth, which can be harmful to you and your family.  

If you live in a particularly humid area or have high groundwater levels, your crawl space should have been constructed with a moisture barrier. Moisture barriers are plastic coverings that keep wood, insulation, and other materials dry. While moisture barriers are an effective preventative measure, they are not always foolproof. 

Whether you have a moisture barrier or not, you should have your insulation inspected at least once every ten years if you live in a humid climate.


Insulation in your crawl space is susceptible to damage from a variety of factors such as weather and animals. Insects and even rodents like to make their homes in insulation, and once they find their way in, they tend to stay. 

Critters damage insulation and leave behind droppings that can become harmful to your home. If your insulation has been damaged, you’ll likely have to replace it sooner than you anticipated.

Type of Insulation

Not all insulation is created equal. Some types of insulation have longer lifespans and are more appropriate for crawl spaces. For example, foam spray insulation is mold resistant and usually stays put until you physically remove it. In most cases, it can last a lifetime in a crawl space.

On the other hand, fiberglass insulation is a cost-effective option for some home areas, but it doesn’t tend to hold up well in crawl spaces. It isn’t particularly mold-resistant and may become ineffective in as few as five years. 

If you are unsure what type of insulation you have, call an insulation installer. They can perform an inspection, let you know what type you have, and tell you what condition your insulation is in.

Consider Replacing Your Crawl Space Insulation

There’s no hard and fast rule for how often your crawl space insulation should be replaced. Like so many other homeowner responsibilities, it comes down to being diligent and informed. If you live in an older home, in a humid climate, or have insulation with a shorter lifespan, it’s a good idea to consider a replacement. 

Replacing your crawl space insulation ensures that your home is protected as it should be and can improve your home’s energy efficiency. If it’s been a while since you’ve been in your crawl space, it’s also a good time to make sure no critters have found their way in and that your space is mold-free.