Crawl Space Encapsulation Cost To Install Vapor Barrier

Here is the average cost to install a vapor barrier in your crawl space and the factors that generally determine crawl space encapsulation cost.

Crawl spaces in homes are vulnerable points through which moisture issues develop. The natural response to such a problem is to have such space(s) moisture-proofed. Here is why crawl space encapsulation is important.

So how much does it cost to put a vapor barrier in a crawl space?

Cost to Install Vapor Barrier in Crawl space

That’s what encapsulation is all about.

Here, a heavy-duty moisture barrier is mostly installed on the floor of your crawl space to contain or prevent moisture penetration.

  • How much to install vapor barrier in crawl space

What are the prices like for moisture barrier installation? This is where our interest lies. We’ll be discussing all crawl space encapsulation costs to give you an idea of what you’re likely to incur for typical installation jobs.

Crawl Space Encapsulation Vs Insulation

A lot of times, people confuse encapsulation with insulation.

In other words, these are used interchangeably. In reality, the two terms are quite different. Crawl space encapsulation has to do with moisture prevention.

Here, an impermeable membrane or heavy-duty moisture barrier like thick polyethylene plastic is used.

Crawl space insulation on the other hand serves a different function. Unlike encapsulation that deals with the prevention of ground moisture and humid air, this mostly involves the prevention of cold floors.

Instead of moisture, insulation deals with the regulation of floor temperature.

You Can’t Beat the Expertise of a Professional

When it comes to crawling space inspection and installation, many homeowners are more concerned about the expenses than getting the job done the right way.

This leads to the adoption of DIY techniques instead of having it professionally done.

Experience has always shown that it’s way better to have your crawl space professionally encapsulated. Here, you tend to get value for money spent as a thorough job is one.

Of course, you’ll need to ensure that only reputable contractors are contacted for the job.

Average Cost of Crawl Space Encapsulation

The process of installing a vapor barrier in a crawl space is also known as crawl space encapsulation.

This is a comprehensive moisture-proofing technique that helps shield your crawl space by using impermeable materials such as plastic liners.

Your location determines whether you’ll require a vapor barrier or not. Locations with humid climates tend to have the most need for a vapor barrier. So, how much does crawl space encapsulation cost? The typical cost range is between $1,500 and $15,000.

The national average for installing vapor barriers is about $5,500.

While these are the main costs, it’s also necessary to state the influencing factors that determine installation costs. Every vapor barrier installation job differs from the next.

This is mainly due to the differences in vapor barrier thickness, type of insulation used, and the number of layers required. Also, certain inclusions may be necessary for particular job types.

For example, areas with excess moisture may require the inclusion of sump pumps or dehumidifiers.

A good crawl space encapsulation job may require the installation of drainage systems, sealing of vents, and possible installation of dehumidifiers in high humidity areas.

In a nutshell, different humid conditions may affect what’s included or what goes into crawl space encapsulation.

DIY Vapor Barrier Installation Costs for Crawl Space

A lot of times, homeowners seek to carry out crawl space encapsulation using DIY methods. This mostly appeals to DIY enthusiasts seeking to cut down on installation costs.

However, the truth is, vapor barrier installation is mostly suited for professionals.

In other words, most homeowners lack the skill to get the job done right.

As such, homeowners lacking the skills should avoid carrying out this procedure themselves.

It’s best to hire a skilled professional to carry out this procedure than losing your structure or home due to a shabby DIY job that leads to greater moisture problems.

  • Are You a Skilled Homeowner?

The only exception to performing DIY crawl space encapsulation will be when you’re a skilled homeowner. If you are, labor expenses are excluded as you’re directly involved in getting the job done.

However, you’ll need a helping hand or a volunteer to get the job done.

There’s a need to buy all the supplies required. Of course, this will cost some money. Some of the basic supplies needed for this job include a 20-millimeter vapor barrier which goes for around $0.50 to $0.70 per square foot.

Installation jobs that require the inclusion of sump pumps will costs around $60 to $170 (pedestal units) and $100$ to $400 (submersible). With dehumidifiers, it will be an added $800 to $1,200.

Other supplies you may need include 4-inch vapor bond tape at about $50 for a 180-foot roll.

An added expense is the foam insulation board. This should be rigid enough and measure about 2-inch in thickness. A 4 x 8-foot sheet of foam insulation board will cost around $26.

  • Professional Installation

For vapor barrier installation to be professionally done, you’ll have to seek professional help. The average national costs are applicable here. All sorts of vapor encapsulation methods are available.

The type used will be determined by your home’s condition.

For example, the installation of a drainage system may be necessary. Under such circumstances, a sump pump may have to be added to the vapor barrier system.

This results in added costs of about $1,300 on average.

Foundation wall insulation is also a possible addition to your vapor barrier insulation job. Here, a professional may decide to have foam boards installed on foundation walls.

This is likely to add between $3 and $300 to your total vapor barrier installation costs. Such costs are inclusive of both materials and labor.

Vent sealing is another likely encapsulation requirement that will add to installation costs. Here, air leaks are targeted and sealed up using vent covers in addition to insulation.

Additional Pricing Details For Crawl Space Encapsulation

To have your crawl space encapsulated, the area is assessed in addition to the moisture content of the soil and humid conditions of the area. The results will determine whether the foundation wall should be insulated or not.

If it will be, you may spend between $0.50 and $1.50 per board foot.

i. Materials and Labor

The cost of materials, as well as labor, play a vital role in determining overall encapsulation costs for crawl spaces. Of course, these are variables that will differ from one job to the next.

What type (in terms of thickness) of vapor barriers will be used for the project?

  • How Much Do Vapor Barriers go for?

One of the key materials for crawl space encapsulation is a vapor barrier. It’s recommended you get a thick (about 20 millimeter thick) vapor barrier for the job due to its durability.

The average cost for a square foot of this material will go for between $0.50 and $0.70.

You’ll have to consult with the technician you’ve chosen to handle the installation job. The length or size of the material necessary to complete the job is estimated by the professional.

To determine the size of the vapor barrier needed, measurements of the crawl space, as well as crawl space walls, are taken.

  • Drainage systems

Are drainage systems going to be included? This question is best answered after determining the humid conditions around your home as well as the soil’s moisture content.

Drainage systems consist of sump pumps which go for an average cost of about $1,300.

Submersible sump pumps tend to cost a couple of hundred dollars more than pedestal pumps or units. The least cost you could incur to get a pump for your drainage system is around $650.

These pumps are most ideal for areas with a high water table.

  • Dehumidifier

Dehumidifiers are possible inclusions to crawl space encapsulation.

Because vapor barriers may not be enough, a dehumidifier may prove handy in reducing the moisture content within your home. On average, the cost of a humidifier is around $800 to $1,200.

Having such dehumidifiers installed will require additional expenses. Such expenses can be categorized as labor-related.

Possible Cleanup and Repairs Before Crawl Space Encapsulation

Before your crawl space is encapsulated, the area needs to be cleaned up first.

During cleanup, preexisting moisture issues may be discovered that require attention or repairs. When there are repairs, the average costs you’re likely to incur are in the region of $1,500.

Some repairs may be extensive and could attract fees as much as $13,000 or more. How much you pay in repair costs is largely determined by your crawl space’s condition.

With crawls space encapsulation completed, problems such as bowing, pest and rodents, sinking foundation, and excess moisture are resolved.

This also includes the elimination of mold and fungus growth among others.

Factors Affecting Crawl Space Encapsulation Costs

There are price-influencing factors when it comes to crawling space encapsulation.

These factors typically affect all installation jobs and include crawl space size, the contractor hired, crawl space condition as well as the materials used.

Vapor Barrier Installation Price Determinants


  • Size of Your Home

How big is your home? Larger homes tend to have wider crawl space to cover. This means more moisture-proofing materials have to be used for the job. Of course, this will translate to more or less time.

A smaller home is likely to take less time to encapsulate its crawl space than a large home.

  • Crawl Space Size

How large is your crawl space? Size plays a role in determining installation costs. The larger your crawl space, the more you’re likely to pay encapsulation fees.

  • Contractor Hired

Different contractors offer varying rates. Each has its pricing structure. This can be of advantage to you when you ask for multiple quotes from various contractors.

  • Crawl Space Condition

We earlier stated that the condition of a crawl space will have an impact on encapsulation costs. When this area is in a state of disrepair, it has to be fixed.

This tends to cost more than when it’s in good shape.

  • Moisture Intensity

Climatic conditions contribute to the cost of vapor barrier installation.

If you live in locations with high moisture or humidity, there’s a likelihood of you spending more to adequately tackle the problem.

This may require the purchase of sump pumps as well as dehumidifiers.

  • Type of Insulation Material

There are different types of insulation materials.

These come in varying thicknesses. While some insulation materials may not be necessary for certain jobs, they may prove important for others.

  • Labor Costs

Labor is a key consideration for vapor barrier installation in crawl spaces.

Due to its labor-intensive nature, a significant part of the costs goes to labor.

A more extensive crawl space encapsulation work will translate to more time spent which directly impacts labor cost to install vapor barrier in crawl space.


When it comes to construction, one of the constant threats to built structures is moisture.

With steady moisture or dampness comes secondary damage which results in mortar cracks (due to freeze-thaw cycles), and the growth of fungi as well as water stains. You don’t want to have any of these developing on your building.

A natural response to moisture problems in homes is the installation of vapor barriers. Vapor barriers serve the key function of blocking moisture or vapor from the soil from getting into or transferring to the building through the crawl space.

The vapor barrier is basically in the form of a plastic liner that covers the dirt floor of the crawl space.

We’ve seen some of the basic materials that may be used for encapsulation jobs. Such materials will have to be bought which adds to your total expenses.

The cost of installing a vapor barrier in your crawl space is quite varied as discussed above. Although we’ve provided the basic pricing information, each crawl space encapsulation job is likely to differ from the other.

So, you’ll need to request a quote for your particular job.

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