House Grail is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How Much Does It Cost to Encapsulate a Crawl Space? (Updated in 2024)

encapsulated crawl space

Crawl spaces are usually the realm of spiders and mice, but they’re an integral part of your home. They cut down on building costs by not needing a concrete foundation and providing a convenient, out-of-the-way spot for HVAC systems, but they can have problems. Crawl space encapsulation is the best way to protect any crawl space, but it can be expensive. Let’s check out more about what encapsulation does and how much you can expect to pay for the service. The cost of an average encapsulation is about $5,500.

divider 4

What Is Crawl Space Encapsulation?

Crawl spaces allow open air to freely flow underneath your house, but they can develop serious problems that can spread to your home. Rats and other pests can penetrate into your home through the crawl space, and mold loves these damp, dark spaces. Thankfully, you can prevent these issues by encapsulating the crawl space.

Crawl space encapsulation involves lining the crawl space with a heavy-duty polyethylene plastic like the type you use as a pool cover. The plastic serves as a barrier to moisture from rainfall, prevents flooding, and keeps pests out. Encapsulation always seals the floors and walls, while lining the ceiling is optional but recommended.

By encapsulating your crawl space, you receive even more handy benefits than those listed above.

Let’s look at a few:
  • Prevents water damage to the foundation
  • Reduces humidity in the home
  • Lowers home HVAC energy costs
  • Prevents mildew growth and odor
Crawl space fully encapsulated with thermoregulatory blankets
Image By: grandbrothers, Shutterstock

house divider

How Much Does Crawl Space Encapsulation Cost?

The cost of crawl space encapsulation dramatically varies based on how large the crawl space is. The cost of an average encapsulation is about $5,500, but that’s not a very good indicator of what you’ll pay. Small spaces can be as cheap as $1,500 to cover, while large homes can run over $10,000.

Aside from the plastic barrier, professionals will add seal vents to the exterior and may recommend installing a sump pump if you live in a low-lying area. Professional-grade dehumidifiers are optional but handy because they remove excess moisture and help prevent mold.

Labor makes up the bulk of the price, as with any job. Roughly half of your total costs will be from materials and the other half from labor. Urban areas typically charge more for this type of work than rural areas because of varying average labor rates. Rates can run as little as $800 per job all the way to $8,000 or more.

Crawl Space Encapsulation Costs:
  • Polyethylene plastic vapor barrier: $.50–$.70 per square foot
  • Tape to secure barrier: $50 per roll
  • Seal vents: $15–$22 each
  • Sump pump and installation: $1,300
  • Dehumidifier and installation: $800–$1,200

To cover a small home’s crawl space of 1,000 square feet with no sump pump or dehumidifier, you can expect to pay as little as $2,500, while homes of 2,000 square feet and up with those accessories can run up to $15,000 or more. On average, though, people tend to pay $5,500.

basement crawl space
Image Credit: JPJPJP, Shutterstock

Other Contributing Factors

There are a few other costs to consider when encapsulating a crawl space. These include the crawl space’s condition, required permits and inspections, insulation, and waterproofing. Let’s break down what those can cost on average.


If the crawl space is structurally damaged, it will have to be repaired before you can encapsulate it. Repairs can cost between $5,000–$15,000, depending on the severity of the damage and what repairs need to be done.

Permits and Inspection

Encapsulation typically requires filing a permit with your local government because it can damage your home if done improperly. The cost depends on your area, but on average permits cost $100–$250. Inspection costs are usually included in the permit fee.


In humid areas, adding insulation to the crawl space in addition to encapsulation can reduce sweating in the space. Batt insulation costs about $300 for a large crawl space, while spray foam insulation costs roughly $.50–$1.50 per square foot. The best type of insulation depends on your crawl space and home, but professionals will be able to recommend which you should use in the event that you need it.


If the crawl space is prone to leaks, professionals may recommend waterproofing to further enhance the encapsulation’s effectiveness and eliminate future water damage. Waterproofing costs depend on a lot of variables, with minor fixes costing a mere $600–$800, while more extensive work can run from $4,000 to more than $10,000.

house divider


Crawl spaces are often overlooked, but they can affect your home’s HVAC costs, provide pests an entry point to infest your home, and develop mold. Crawl space encapsulation can cost from $1,500 for small homes to over $10,000 for large houses, with the average being $5,500. If you need extras like a sump pump, waterproofing, or insulation, this figure can get a lot larger.

Featured Image Credit: grandbrothers, Shutterstock


Related posts

OUR categories

Project ideas

Hand & power tools