Crawl space encapsulation, or crawl space sealing, is a great way to turn your damp, dirty, moldy crawl space into a clean area where mold and mildew can’t grow. Basically, it blocks humidity and keeps your home’s floor system dry and healthy. You can even use the living space beneath your home as an additional storage room.

What is crawl space encapsulation?

Crawl space encapsulation is a process that’s done by adding a heavy-duty moisture barrier to the floor of your crawl space, foundation vents, and insulated walls. It’s one of the most effective ways to seal the space completely. To make it even more effective, you can use a crawl space dehumidifier. It helps regulate the moisture levels of that area.

How does crawl space encapsulation differ from insulation?

Polyisocyanurate Insulation in home

Homeowners often get confused between crawl space insulation and encapsulation. However, the two fulfill quite distinct purposes. If you’re dealing with problems such as ground dampness and humid air, crawl space encapsulation works great. But if you’re dealing with cold flooring, you’ll need crawl space insulation.

Pros and cons of crawl space encapsulation

Investing in crawl space encapsulation is a good idea as it makes your home a safer and more pleasant place to live in. And, it boosts the value of your house significantly. Every potential home buyer is impressed with a dry, clean crawl space – not an aging or an open vented crawl space that’s infested with mold.

Let’s list the pros of crawl space encapsulation more systematically.


Crawl space encapsulation has several benefits. It’s definitely worth the investment of your time and money.

Prevents moisture

Moisture seeping into your crawl area can result in a lot of water damage. Moreover, excessive moisture problems can affect the strength of your home’s floor joists, beams, and foundation walls if not controlled. As a result, these will eventually expand and bend. And, the wood may decay. Replacing wood rot can be a costly and time-consuming procedure.

Moisture can also cause the concrete of your foundation to shift and break. To prevent all these issues, always use a dehumidifier along with crawl space encapsulation to maintain the optimal moisture level. 

Prevents mold and mildew

As moisture continues to build up in your crawl space, you may find fungus, mold, and mildew beginning to grow – all of which cause a foul odor that can easily make its way into your home. Moreover, the fungus can affect the air quality of your home and cause serious health problems. 

Makes your home comfortable to live in

Crawl space encapsulation improves healthy living conditions as well as the air quality in your home. It also improves the structural integrity of your house’s foundation by preventing water from building up.

Another advantage is that encapsulation adds a layer of insulation. It helps keep your hardwood floors or tile floors comfortable to walk on all year. 

Lowers home heating and cooling costs

Encapsulation helps make your home more energy efficient – effectively lowering your energy bills. As you insulate, condition, and encapsulate your crawl space, you will notice that you use your HVAC much less frequently than before. Experts believe that your energy savings can be up to 15 to 20 percent. 

Reduces the risk of pest infestations

Cockroaches and other pesky insects find a way into your home through gaps in the doors and windows as well as crawl spaces. They are especially drawn to damp, dark crawl spaces. And once they enter your home, it hardly takes them any time to grow in number. And then, it can be quite expensive and challenging to get rid of them. Proper sealing will block moisture and deter pests from entering the area.


Here are a few downsides to encapsulation that you should be aware of.

High upfront cost

The upfront costs for crawl space sealing may be anywhere between $3,000 and $8,000. It may go as high as $30,000 – depending on several cost factors. This is a major investment for someone who’s on a tight home remodeling budget. However, keep in mind that this investment may help you save money on expensive repairs later on. 

Requires maintenance

After adding encapsulation to your crawl space, you will need to ensure its proper upkeep so that it’s working properly. This could include regular maintenance checks by a professional crawl space contractor.

Requires HVAC upgrades

You will need to update your HVAC system. This is an important step toward ensuring that the system is safe and efficient enough to run in an encapsulated crawl space.

Keep in mind that this type of encapsulation may limit the airflow in your home. This can be a slight matter of concern if you have a combustion-based furnace. 

How much does crawl space encapsulation cost?

floor insulate

The average cost for crawl space encapsulation is approximately $7,500. That translates to $3 to $7 per square foot. This includes a drainage system, insulation, a high-performance vapor barrier installation, crawl space repairs, sealing, and dehumidifier. 

However, the total cost can range from $3,000 to $30,000, depending on a variety of factors such as the size of the crawl space, its condition, the materials used, the contractor you hire, and additional features.

For example, crawl space waterproofing will cost you $1,500 to $15,000, depending on the size, condition, and accessibility of the crawl space. 

Last thoughts

Crawl space encapsulation is an easy way to deal with many air and moisture problems. A clean, properly sealed crawl space can help prevent mold growth and musty odors. Most importantly, it improves indoor air quality and effectively blocks the entry of rodents and insects. And last but certainly not least, it helps ease the load on your HVAC system – improving its efficiency. 

What are the pros and cons of crawl space encapsulation? was last modified: December 16th, 2022 by Ramona Sinha
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