The crawl space quickly accumulates and locks in moisture and humidity, especially during the warm spring and summer months. This can lead to all sorts of problems, from health issues for the dwellers above and poor household climate control to structural damage on the piers and floor. Crawl space encapsulation is an effective permanent solution to this problem. Find out the crawl space encapsulation pros and cons.

Crawl space encapsulation essentially creates a dry buffer between the dirt floor of the crawl space, its walls, and the floor above. The process begins with lining the crawl space floor and walls with a reinforced polyethylene vapor barrier. This barrier prevents ground moisture from rising to the floor. All vents are then sealed to keep out humid air. At this point, insulation may be added to the crawl space walls to improve thermal resistance. Finally, a dehumidifier is installed to actively expel moisture from the crawl space.

Let’s look at the pros and cons of crawl space encapsulation and why it might be necessary to encapsulate your crawl space.

Advantages of Crawl Space Encapsulation

Crawl space encapsulation is beneficial in several different ways. Here are the main perks of keeping crawl space moisture and humidity levels in check via encapsulation:

Cuts Heating and Cooling Costs

Crawl space encapsulation adds a thick layer of internal insulation around the crawl space walls. Plus, the vapor barrier covering the floor creates a fair amount of insulation between the floor and the ground. This insulation protects the crawl space and the floor above it from external temperature extremes — keeping the area warm in the winter and cool in the summer.

Passive insulation makes the house more energy-efficient, meaning the HVAC system doesn’t have to work as hard to keep the house cozy. Lower AC usage translates to lower energy consumption and lower electric bills.

Improves Indoor Air Quality

A good portion of the air that organically makes its way into the house comes from the crawl space. Encapsulating the crawl space is an easy way to improve indoor air quality. Encapsulation removes toxins and unwanted humidity in the air circulating between the crawl space and the rest of the house.

Improved air quality promotes good health by eliminating allergens, dust, and pathogen-ridden air vapor. It also boosts emotional and mental wellness. For instance, the Sick Building Syndrome (SBS) is closely linked to poor indoor air quality.

Prevents Mold and Mildew Growth

crawl space encapsulation pros and cons

Mold and other fungi such as lichen and mildew thrive in dark, moist, humid places. An unsealed crawl space is an ideal habitat for fungi colonies. But eliminating moisture and keeping the air in constant circulation inside the crawl space makes the environment inhospitable to mold.

A mold infestation in any part of the house is not something to take lightly. Mold’s characteristic musty odor is just the start of the problems. As mold grows, it releases dust-like spores and other micro-toxins into the air that can cause allergic reactions and respiratory illnesses. Also, mold feeds on the material it grows on, causing it to rot or wither.

Keeps Pests Away

Some insects and rodents such as roaches, beetles, crickets, rats, and moles like to make crawl spaces their home. The dark, humid, unkempt, rent-free environment is just what they need to catch food and reproduce. These unwelcome guests can carry serious diseases and get down to all sorts of mischief.

Encapsulating the crawl space closes it off to vermin and eliminates the risk of harmful infestations. In fact, sealing the crawl space is one of the best ways to control some household pests such as roaches and ants because that’s where they go to hide and breed.

Protects the House’s Structural Integrity

Excessive moisture build-up in the crawl space can weaken load-bearing piers and foundations, compromising the house’s overall structural integrity. A combination of dampness, mold, and pests can damage the wooden, metal, or concrete structure holding up the floor or the building itself. Encapsulating the crawl space prevents this from happening.

Improves the Floor’s Comfort and Longevity

If your house has wooden flooring, a damp crawl space could ruin it. Moisture-related damages on wooden floorboards call for expensive repairs and replacements. And without proper insulation, the crawl space lets in freezing air during the winter months, making the uncarpeted floor unbearably cold.

Encapsulating the crawls space extends the floor’s lifespan and helps keep it warm even without underfloor heating.

Disadvantages of Crawl Space Encapsulation

Are there any negatives to crawl space encapsulation? The only downside is that it can be costly since it’s a major home renovation. It costs about $5,500 to encapsulate the crawl space of an average American home, but it can go as high as $15,000. Home upkeep costs could also go up due to additional maintenance. Additionally, sealing the crawl space means that you cannot use it for other purposes such as storage. But really, the benefits of encapsulation far outweigh any inconveniences and more than justify the cost.

Is Crawl Space Encapsulation Necessary?

Should crawl space be sealed? Crawl space encapsulation is not a requirement; it’s an optional home renovation. But it’s a necessary solution for getting rid of unwanted moisture, pests, mold, and foul air in the crawl space. Plus, it makes the house healthier, safer, and more comfortable to live in.

Does Crawl Space Encapsulation Increase Home Value?

Is it worth it to encapsulate crawl space? Yes, it is. On top of all the benefits, encapsulating the crawl space adds value to the property. Unfortunately, you can’t really put a figure to how much value crawl space encapsulation adds to a house. But an encapsulated crawl space is a key consideration in appraisals and an important selling point when closing a deal.

When to Consider Crawl Space Encapsulation

It’s best to encapsulate your crawl space if it starts being problematic. Here are some of the telltale signs that the crawl space needs sealing:

  • There are recurring mold and mildew patches.
  • The cost of cooling and heating keeps going up.
  • The HVAC is working overtime.
  • There is dampness and condensation around the house.
  • There are chirping and squeaking noises from under the floor.
  • There are signs of moisture damage around the crawl space walls and piers.
  • A musty smell is emanating beneath the floorboards.

However, prevention is always better than cure. By the time you start noticing these signs, the humidity or infestation problem might already be so bad that it’d take a lot more to fix than simply installing the encapsulation. The best bet is not to wait until something goes wrong to encapsulate the crawl space.

How Long Does It Last?

On average, crawl space encapsulation lasts between 10-15 years. But some moisture and vapor barriers are rated for up to 20 years. Also, the encapsulation’s lifespan may depend on the quality of the material used, the area’s preparation before encapsulation, the overall quality of the job, and the ongoing care and attention.


Crawl space encapsulation is a quick and easy way to preserve and upgrade your home. In addition to boosting the property’s value, encapsulation makes the house more energy-efficient and immune to humidity-related damages such as mold and rot. It also improves the quality of life for the dwellers by enhancing the house’s comfort and safety.

If crawl space encapsulation seems unnecessary or expensive, consider all these long-term benefits, many of which you can’t put a price on. And once the project is completed, it’s virtually maintenance-free; you only have to inspect the crawl space once a year to ensure the seals are holding up nicely.

Moisture Loc is your go-to specialist for crawl space encapsulation. Our GreenSpace™ Sealed Crawl Space System keeps moisture and humid air out of the crawl space, eliminating all the associated risks. Click here to learn more about our professional crawl space encapsulation services, or contact us to request a free quote.