A crawl space is the area between the first floor of a home and the ground below in a raised foundation system. While originally designed for flood protection, crawl spaces are useful for buildings on sloped ground and can house plumbing pipes, electrical wires, and HVAC systems. However, open crawl spaces can collect too much moisture and attract rodents or pests if not properly encapsulated.

Crawl space encapsulation costs an average of $5,500 but can range from $1,500–$15,000, depending on the work required. Our guide breaks down each price factor and answers other essential questions about crawl space encapsulation.

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What Is Crawl Space Encapsulation?

A crawl space is the gap between the ground and a home’s first floor. The minimum height of a crawl space is 18 inches from the dirt to the bottom of the framing but may be larger. Crawl spaces must have ventilation so moisture doesn’t build up under the home, causing fungal decay or water damage. However, air circulation may not be enough to reduce moisture buildup in humid climates. You may need to encapsulate your crawl space in these cases.

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What Are Signs You Should Encapsulate Your Crawl Space?

Here are some signs that you need to encapsulate your crawl space:

• Indoor allergy symptoms
• Mold or mildew growth in the crawl space
• Musty odors in your air ducts if the system in located under the house
• Pest infestation in the home
• Signs of excess moisture in your home, such as sweating windows

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What Is The Average Crawl Space Encapsulation Cost?

How much your crawl space encapsulation costs depends on the following factors:

• Size: Larger crawl spaces cost more to encapsulate.
• Condition: You may need to pay additional repair costs if the crawl space is in poor condition.
• Labor: Labor usually accounts for 50% to 70% of the total cost.
• Permits and inspection: Crawl space encapsulation typically requires a permit.
• Materials: Vapor barriers, insulation, and more comprise 30% to 50% of the total cost.

Cost by Size

Your crawl space’s size has one of the biggest impacts on price since larger areas require more materials and labor to encapsulate. A basic encapsulation project costs between $3 and $7 per square foot, but the cost can go up to $10 per square foot for crawl spaces with an extensive moisture problem.

Cost by Condition

Contractors may need to perform repairs before encapsulating your crawl space. Foundation repairs are pricey, often costing $2,000–$7,000 to repair a moderate problem. Floor joists, foundation walls, posts and beams, and other areas suffering from water damage may also need treatment, repair, or replacement. The area may need to be cleaned, which includes removing and disposing of any debris.

Labor Cost

Having professional contractors encapsulate your crawl space accounts for 50%–70% of the total. That means paying anywhere from $2,250–$10,500 for a 1,500-square-foot home.

Cost of Permits and Inspection

Work done to a home’s crawl space usually requires a permit. Permit costs vary by city but are usually within the $100–$250 range. This price often includes a formal inspection when the project is complete to ensure the work is up to local code.

Cost of Materials

Materials usually account for 30% to 50% of encapsulation costs. Here are the materials you can expect to pay for.

Vapor Barrier and Tape

A vapor barrier is plastic sheeting that waterproofs the crawl space. It’s priced by thickness and ranges from 6 millimeters ($0.05–$0.20 per square foot) to 20 millimeters ($0.40–$0.60 per square foot). Thicker sheeting is more durable and thus more expensive. Vapor barrier installation also requires waterproof tape to seal the edges, costing anywhere from $18–$50 per roll.

Vent Covers

Instead of remaining open for ventilation from outside air, your crawl space vents will need to be sealed to prevent air and water from coming in. Sealing vents typically costs $10–$22 per vent, plus another $60–$150 if you want a crawl space access door.

Insulation

Crawl space insulation prevents air leaks and increases your HVAC system’s energy efficiency. Fiberglass batt is the least expensive material at $0.60–$1.10 per square foot, but it’s usually not recommended for high-humidity environments because it can harbor mold and mildew. Spray foam insulation is more affordable at $1.00–$3.50 per square foot, but it must be used carefully around pipes or wires because it’s extremely difficult to remove. Rigid foam board insulation costs $2.50–$3.00 per square foot. It’s the most durable and easiest to work with but typically the most expensive.

Dehumidifier

You may need to install a dehumidifier to continuously remove excess moisture from your crawl space. A dehumidifier large enough to work throughout the entire space plus the wiring to power it typically costs between $800 and $2,000 to install.

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What Are Additional Cost Considerations for Crawl Space Encapsulation?

The following costs aren’t applicable for every encapsulated crawl space, but they may add to your project’s total price.

Drainage

If you need a dehumidifier, you’ll also need a place to drain the water it pulls from the air. A French drain may suffice in drier climates or homes with above-ground crawl spaces. Homes in areas with a high water table may require a sump pump to actively pull water away from the foundation. A full drainage system can cost anywhere from $600–$1,800 to install.

Hazardous Material Remediation

If your crawl space has had moisture problems for a long time, the air quality may be hazardous from mold or fungi. Mold removal can cost $500–$4,000 depending on the problem’s extent. If asbestos is present in old building materials, you could pay $1,800–$2,800 to remove it.

Pest Control

Rodents, insects, or other pests will need to be removed before crawl space encapsulation can begin. A small infestation may cost as little as $200 to treat, but a substantial problem like termites can cost up to $4,000 to treat and repair damage.

Free quote: Get your quote from a foundation expert today

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What Are the Benefits of Crawl Space Encapsulation?

Though crawl space encapsulation can be expensive, here’s what you stand to gain:

• Fewer musty odors
• Higher home resale value
• Lower energy bills
• Potential tax rebates
• Reduced risk of water damage, mold, and pest problems
• Reduced risk from radon gas

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How To Save on Crawl Space Encapsulation

Here are some ways to reduce costs, even if you hire a professional.

• Do as much cleaning and preparation as possible unless toxic materials are involved.
• Get estimates from at least three contractors to find the best deal.
• Ask about package deals with other home improvement jobs on your list.

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Should You DIY vs. Professional Crawl Space Encapsulation?

Crawl space encapsulation is a risky do-it-yourself (DIY) job due to the cramped space and high stakes of the project. Here’s the difference between hiring a professional and doing it yourself.

Professional Crawl Space Encapsulation

Most homeowners should have a professional encapsulate their crawl space. Particularly if moisture is a large problem, professionals will have the training and experience for complicated work such as creating a drainage system and wiring a dehumidifier. Additionally, working in a small, musty space underneath a house is often unpleasant. Professionals can get the job done quickly and effectively, and they typically offer a warranty on their work.

DIY Crawl Space Encapsulation

Most of the materials you’ll need, such as a vapor barrier and insulation, are available at hardware stores. However, if you don’t know what you’re doing, you risk trapping moisture inside the space and making it worse. Although you can save money by doing it yourself, crawl space encapsulation is usually a job for professionals.

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How To Hire a Professional Crawl Space Expert?

Hiring a crawl space encapsulation contractor is similar to hiring any other type of contractor. Here’s what to look out for.

• Hire an independent noncommissioned professional to inspect and recommend a solution for your issue.
• Find a contractor who has specific experience to address that issue.
• Make sure the contractor is licensed and insured.
• Check the company’s Better Business Bureau (BBB) rating and accreditation.
• Look at customer reviews on sites such as Yelp and Trustpilot or ask for references.
• Get a signed contract with a list of itemized charges in writing before work begins.

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Our Conclusion

You should hire a professional contractor to encapsulate your crawl space in most cases. Foundation and framing problems from water damage can be expensive to repair, so it’s best to ensure the job is done right the first time. Many crawl space contractors offer a free inspection and estimate, so do some research before making your choice.

Free quote: Get your quote from a foundation expert today

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FAQ About Crawl Space Encapsulation Costs

How much does it cost to encapsulate a 1,000-square-foot crawl space?

It typically costs $3,000–$7,000 to encapsulate a 1,000-square-foot crawl space.

What is the average cost to encapsulate a crawl space?

Encapsulating a crawl space usually costs $3–$7 per square foot for an average of $5,500.

Is crawl space encapsulation worth the cost?

Encapsulating and waterproofing your crawl space is usually worth it, particularly if you live in a humid climate or an area with a high water table. You’ll protect your home’s foundation from water damage and pest infestation plus reduce your energy bills.

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