How much does it cost to have a vapor barrier installed?

Author: Dr. Braden Shanahan  |  Last update: Sunday, June 8, 2025

Vapor Barrier Installation Cost Per square foot, expect the crawl space vapor barrier cost to land between $1.35 and $2 per square foot, or a total of between $1,500 and $4,000 for labor and materials.

Is a vapor barrier worth it?

Yes, laying down a vapor barrier is a smart move. It prevents moisture from penetrating your crawl space, guaranteeing your home stays dry and shielded from damage.

How much does it cost to encapsulate a 1200 square foot crawl space?

Crawl space encapsulation costs homeowners an average of $5,500 but typically ranges from $1,500–$15,000. See which factors will impact your total cost. Mark Howey is a licensed California building contractor with more than four decades of experience in the construction industry.

What is an alternative to vapor barrier?

Carton board air barrier paper is an excellent alternative to vapor barrier plastic.

Can I install vapor barrier myself?

Provided you're not claustrophobic, installing a vapor barrier is a project most homeowners can DIY. You will need to calculate the square footage of your crawl space, so you can buy the appropriate amount of liner.

How Much Does A Vapor Barrier Cost?

How much should I charge to install vapor barrier?

An average vapor barrier installation costs $2 to $4 per square foot or between $1,200 and $4,000 for materials and labor. *Labor costs to install add $1.50 to $3.00 per square foot on average.

When should you not use a vapor barrier?

Because a vapor barrier is a low permeable barrier, it keeps moisture from passing through. This is beneficial to keep moisture away from a dry surface but will trap moisture behind it if installed on a water-damaged concrete wall, causing the wall to fail further.

What are the disadvantages of a vapor barrier?

Cons: This material is fairly flimsy and can be easily damaged during installation. It incorporates limited resistance to punctures and tears. Any penetrations, such as for an electrical junction box, must be taped and sealed in order to form an effective barrier.

Can I use Tyvek as a vapour barrier?

No, DuPont Tyvek is not a vapor barrier. It is breathable, allowing moisture vapor to pass through it.

What happens if you don't have a vapor barrier?

“For minor projects, the absence of a vapor barrier leads to water intrusion, leading to an unstable foundation or a cracked slab.” The American Society for Testing and Materials (ASTM) outlines national standards for underslab vapor barriers.

Does homeowners insurance cover crawl space?

It depends on your provider and policy, but the general rule of thumb is that if it's preventable, it's not covered. This includes crawl space repairs resulting from poor moisture management, pest infestations, and neglected maintenance.

What are the negatives of crawl space encapsulation?

Crawl space encapsulation has a few negatives worth considering. Initially, the process can be costly and may not fit every budget. Moreover, if not done correctly, it could trap moisture already inside the crawl space, leading to mold growth and wood rot.

Does crawl space encapsulation qualify for tax credits?

Encapsulation falls under the insulation and air-sealing category. Under the tax credit, you can claim 30% of the cost, up to $1,200. A crawl space that costs $4,000 to encapsulate maximizes this tax credit. If your crawl space costs less than $4,000 to encapsulate, you will not receive the full $1,200 in credit.

Where is the best place to put a vapor barrier?

Vapor barriers are installed along, in, or around walls, ceilings, and floors. Of course this is done to prevent moisture from spreading and potentially causing water damage.

What is the life expectancy of a vapor barrier?

A high-quality crawl space vapor barrier can be an effective solution for many years, as long as it is not damaged or punctured along the way. Generally, a crawl space vapor barrier that has been correctly installed by a professional and made of high-quality materials can have a lifespan of 20 years or more.

Can I just use plastic as a vapor barrier?

You can use plastic if you put polyethylene between your drywall and the wall studs. This way, you should get a tighter wall without trapping moisture inside the exterior walls. If you are framing out a below-grade basement, however, do not use plastic as a vapor barrier.

What can I use instead of vapor barrier?

Materials such as rigid foam insulation, reinforced plastics, aluminum, and stainless steel are relatively resistant to water vapor diffusion. These types of vapor retarders are usually mechanically fastened and sealed at the joints.

What is the difference between a moisture barrier and a vapor barrier?

Both are designed to keep moisture out of your home and can be made from various materials. But there are a few key differences, the most apparent being that moisture barriers are better at keeping out liquids, and vapor barriers are better at keeping out water in its gaseous state.

Does house wrap count as a vapor barrier?

Water Vapor Permeability: To limit the possibility of mold and rot, house wraps that offer certain levels of vapor permeability are usually best. Look for products rated at 1 Perm (US rating) or 60 Ng (Canadian rating), as these are benchmark permeability rates for what defines a type II residential vapor barrier.

Do vapor barriers cause mold?

Install a New Vapor Barrier

If your vapor barrier was damaged or not installed correctly, it's important to replace it with a new one. This will help prevent moisture from seeping into your crawl space and creating the perfect environment for mold growth.

Are vapor barriers expensive?

Vapor Barrier Installation Cost

Per square foot, expect the crawl space vapor barrier cost to land between $1.35 and $2 per square foot, or a total of between $1,500 and $4,000 for labor and materials.

How do I know if I need a vapor barrier?

If you live in a mixed climate – hot and humid with several heating months in the winter, you probably need a vapor retarder. Specifically, if you live in climate zones 4C (marine), 5, 6, 7 and 8. Not sure your climate zone? You can check here.

Should you put plastic behind drywall?

Yes, covering your insulation with a vapor barrier plastic before installing drywall is crucial.

Does vapor barrier need to be completely sealed?

This reduces condensation on surfaces, helping to protect against moisture damage. It's also important to ensure that the barrier is completely sealed so that no moisture can get through it. Using staples or tape along all edges and seams will help create a strong seal.

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