How to Seal a Crawl Space

old home with sealed crawl space

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If you’re concerned about mold or other issues, you may wonder, “Should the crawl space be sealed?”

Your crawl space plays an important part in protecting your home. However, it can’t do its job if it’s not in top condition.

To learn more about how to seal a crawl space, keep reading.

What Does a Crawl Space Do?

In part, your crawl space supports your flooring and everything that’s above it. Your crawl space also serves as a barrier between the ground and your house.

A crawl space usually has ventilation to the outside. Otherwise, it should have ventilation to an adjoining basement area. Ventilation allows air to circulate below your house.

When your crawl space is ventilated to an adjoining basement, it can have a desirable effect. Ventilation will help to keep your home warmer when it’s cold outside.

Common Crawl Space Problems

Encapsulation can help to resolve many crawl space problems. For instance, you may have environmental problems. These issues can include high humidity or toxins in your air.

You could also have other crawl space-related problems. These problems might include:

• Foundation movement
• Mold
• Radon
• Vermin
• Wall bowing

A damp crawl space can lead to pesky problems like termites. It’s important to address these kinds of matters. Left unresolved, they can lead to the instability of the structure of your home.

You may have yet to experience these kinds of problems. Nevertheless, an encapsulation system could serve as a wise investment. It can help you to get ahead of these kinds of issues before they become expensive to repair.

Should the Crawl Space Be Sealed?

If you have a crawl space, you must manage moisture in that area. Crawl spaces can collect dampness easily. An encapsulation system can prevent problems with moisture.

Accumulated dampness can lead to health problems. Dampness can also make your home unsafe.

About half of the air you breathe comes from your crawl space. Your home’s air quality directly correlates to your health.

Poor air quality can worsen existing health issues. It can even cause some conditions to develop.

You should continually monitor your foundation for signs of damage. For example, you’ll want to look for cracks in the walls of your crawl space. You should also look for any signs that might indicate water’s getting under your home.

Leaking pipes, condensation, and downspouts can all add excess moisture to your crawl space. Fortunately, an expert foundation service can help you keep out unwanted critters and keep your foundation dry.

Staying on Top of Problems

You should never observe standing water in your crawl space. Gutter extensions are a common solution for this kind of issue. They’ll divert water away from your foundation.

Still, you should have a foundation service perform a soil assessment if you do see standing water in your crawl space. The foundation service may also recommend the installation of a drainage system around the perimeter of your home.

The Solution for a Damp Crawl Space

Once you’ve ensured proper drainage away from your home, an encapsulation system will protect it from other issues. The encapsulation process involves installing a vapor barrier. A foundation service will install it across the span of your crawl space.

Even with proper drainage, it’s possible for moisture to get into the soil or concrete in your crawl space. The vapor barrier prevents the moisture from evaporating in your crawl space and causing damage. The foundation service may also recommend the barrier to guard against extreme temperature fluctuations, depending on where you live.

How Much Does It Cost to Seal a Crawl Space?

Encapsulation can cost anywhere from $1,500 to $50,000, depending on the size of your home and other factors. On average, homeowners spend around $5,500 for a full crawl space encapsulation system. This cost includes labor and supplies.

The cost of encapsulation will also vary depending on the condition of your crawl space. The market costs for materials also vary. Finally, contractor rates vary among service providers.

Encapsulation Cost Variables

A foundation company will charge different rates for various services. For instance, waterproofing may cost around $4,600. Again, the cost of installation will vary depending on the size of your home.

There are different rates for the various thicknesses of vapor barriers. Also, the foundation service may recommend multiple layers of barriers.

The price of various types of insulation could also vary. Likewise, the cost of equipment, such as dehumidifiers and sump pumps, can also vary in price.

Understanding Encapsulation

The foundation service might simply recommend a thin, single-layer plastic liner. In other instances, however, they might suggest a thick multilayer liner.

Properly conditioning a crawl space is critical. A resolution for dampness in your crawl space may also include the installation of a dehumidifier, sump pump, and drainage trenches.

You may live in a hot, humid climate. If so, your crawl space faces a greater risk for damage from condensation.

Otherwise, you may live in an older home. In that case, the foundation service may recommend venting your crawl space.

In either case, moisture can threaten the stability of your home. A professional foundation repair service can evaluate and fix any existing damage. They’ll also prevent any future damage with the installation of the new encapsulation system.

Let’s have a closer look at services that might go alongside encapsulation.

Crawl Space Wall Insulation

A foundation service may recommend insulation for your crawl space. The price for installing crawl space insulation will vary depending on the size of the space. It will also differ depending on the ventilation method used for your crawl space.

If the foundation company recommends spray foam, the installation could cost anywhere from $0.50 to $1.50 per square foot. Also, insulation batting prices can vary. You could pay anywhere from three dollars for a single roll of insulation up to $300 in material costs for a larger installation.

Vapor Barrier Material Costs

It’s important to use the right plastic for your vapor barrier. Thin, cheap plastic can rip easily.

A tear in your vapor barrier will compromise the protection of your crawl space. A thicker plastic, however, will resist tearing. In turn, it will keep out moisture effectively.

A standard vapor barrier is about 20 mm thick. This material can cost anywhere from $0.50 to $0.70 per square foot.

The foundation service will also need to tape the vapor barrier in place. A 180’ x 4” roll of vapor barrier tape might cost about $50.

Again, labor charges for the installation will vary depending on the service. However, a professional foundation service will include the cost of all labor and materials in their quote for the project.

Sealing Air Leaks

If you have an existing HVAC system, vents can serve as a low-cost solution for fixing moisture in your crawl space. They’ll help to keep the inside of your home dry.

In this scenario, the foundation service may also recommend sealing a crawl space to prevent air leaks. For this part of the project, they’ll seal any exterior vents and leaks.

If you need vent covers, these features could cost anywhere from $15 to $22 each. The foundation service will also insulate and stop leaks around the rim joists, sill plates, and any penetrations for pipes or cables.

Repairing Drainage

Your home may lie below ground level. Alternatively, you could live in an area with a high water table. In either case, the foundation repair service may recommend a sump pump along with your encapsulation system.

A pedestal sump pump could cost anywhere from $60 to $170. Meanwhile, a submersible sump pump could cost between $100 and $400.

The full sump pump installation might cost about $1,300 on average. You can spend anywhere from $650 to $1,800 for an appropriately sized sump pump installation.

Dehumidifier Systems

You may live in a region with high humidity. In that case, your vapor barrier will need help preventing moisture buildup.

In this case, the foundation repair service may recommend a dehumidifier for your crawl space. A crawl space dehumidifier unit can cost between $800 and $1,200 plus the cost of installation.

Here, it’s important not to confuse a household dehumidifier with one that’s designed to keep your crawl space dry. A crawl space dehumidifier is much larger. Manufacturers also design this kind of unit to manage a much higher level of moisture than you’d find in your home.

Having Crawl space Problems? We Can Help!

We hope our brief overview has helped you get a better understanding of the answer to the question, “Should the crawl space be sealed?” If you’re concerned about the condition of your crawl space, Crawlspace Medic has answers.

Don’t wonder about whether your crawl space can protect your family and home. Schedule your free crawl space inspection today.

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