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How to Install a Vapor Barrier in Your Crawl Space

A Foundation Recovery Systems technician installing a vapor barrier.


Dealing with a leaky crawl space is frustrating, but there are several waterproofing solutions to keep your space safe and dry.

Installing a vapor barrier, a key step in encapsulation, alongside perimeter drainage and a sump pump, effectively redirects moisture away from your home. This article aims to address when should you consider a vapor barrier, and how it fits into the overall encapsulation strategy.

Signs Your Crawl Space is Leaking


Before you invest in a vapor barrier, you’re going to need to look over your crawl space and determine how severe the leaking actually is. When looking, keep an eye out for the following signs: 

  • Cooler Temperatures: Noticeable drops in your crawl space temperature due to increased dampness indicate potential leaks. Use a thermometer to monitor changes.
  • Damaged Belongings: Regular checks on items stored in your crawl space can reveal water damage signs, like curled papers, rotting fabric, or warped wood.
  • Pest Infestations: Cracks allowing moisture in may also let pests into your crawl space. Watch for signs of critter or insect invasions.
  • Damp Walls: Moisture on your crawl space walls is a clear leak indicator, showing that water is entering and lingering.
  • Mold: Look for mold growth, a sign of a damp environment. Address mold promptly and consider waterproofing solutions to protect your home

What is a Vapor Barrier?

A Foundation Recovery Systems technician installing a vapor barrier.

Now that you’re aware of the signs, when is a vapor barrier actually necessary? Vapor barriers, thick white sheets that repel water from your crawl space, prevent air and gases from penetrating, thus protecting your stored items from moisture and groundwater.

They are perfect for crawl spaces experiencing wall dampness and occasional floods. Encapsulating your crawl space with a vapor barrier offers a permanent solution to seal it off from the earth effectively.

Waterproofing Your Crawl Space With a Vapor Barrier

Vapor barriers are an essential part of the encapsulation process your crawl space can undergo if it experiences frequent or severe leaks. In general, the encapsulation process includes the following steps:

  • Dry out the crawl space: Remove any standing water or dampness before beginning encapsulation. For significant water removal, discuss installing a temporary pump with your contractor.
  • Locate the leak: Trace water paths to find leaks in walls or joints. If the leak is elusive, it might be a foundation crack—consult with your contractor for foundation waterproofing.
  • Seal the leak: Plug identified leaks to ensure dryness during encapsulation.
  • Remove old insulation: Discard water-damaged insulation to prevent pathogen spread and mold growth.
  • Install vapor barrier: After removing old insulation, install the vapor barrier, making accommodations for pipes, electrical circuits, and vents.
  • Enhance waterproofing: Discuss additional waterproofing methods with your contractor, such as combining a vapor barrier with a dehumidifier for extended protection.

Enhancing Your Crawl Space with Encapsulation Solutions

A vapor barrier’s thick, protective layer is just the beginning. It is just one component of Foundation Recovery System’s recommended encapsulation solution. Here are some of the other components:

Dehumidification for Dryness and Durability

A Foundation Recovery Systems dehumidifier.

Pairing a vapor barrier with a dehumidifier elevates the effectiveness of keeping your crawl space dry.

Dehumidifiers not only extract moisture but also maintain an environment where wooden support beams can remain robust, free from mold and rot.

Our specifically designed crawl space dehumidifier, boasting an ENERGY STAR® rating for its unique heat exchange system, not only promotes a healthier space but also offers energy efficiency and cost savings.

Vent Covers for Moisture Control

sealing a crawl space vent

Open vents were once though to help air circulation in your crawl space, but we now understand that open vents often do more harm than good by inviting moisture and humidity into the area. The solution lies in installing crawl space vent covers.

Once in place and properly sealed, these covers effectively block external air and moisture from penetrating your crawl space, providing an essential layer of protection. This measure is especially effective when combined with other crawl space solutions, ensuring a comprehensively safeguarded area beneath your home.

Professional Encapsulation Service is Your Best Choice

While a select group of homeowners with specific expertise might feel capable of tackling crawl space encapsulation on their own, the complexity and importance of this task often make it best suited for professional hands.

Foundation Recovery Systems specializes in providing comprehensive, expert solutions for crawl space problems, ensuring that every aspect of encapsulation is handled with precision and care. Our experienced professionals use state-of-the-art equipment and techniques to ensure your crawl space is sealed and protected for the health and stability of your home backed by warranties.

Contact Foundation Recovery Systems

Foundation Recovery Systems CFI in front of home with wrapped car

Remember, your home is a significant investment. While understanding how to install a vapor barrier in your crawl space is beneficial, entrusting this task to professionals guarantees precision, efficiency, and the right outcome from the start.

With Foundation Recovery Systems, you receive expert encapsulation services and a partnership dedicated to the health of your home. Reach out to us today to schedule your free inspection, and let us guide you through the first steps toward a dry, healthy crawl space, ensuring your foundation remains solid for years to come.

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Leah Leitow

Leah Leitow

Content Writer

Leah is a Content Writer for Groundworks with nearly ten years of experience working in the foundation repair industry. Her experience ranges from working with homeowners to find the right solution to training inspectors and staff. In her background as a Michigan journalist, she gained invaluable insight into people's lives throughout our state. Leah lives in metro Detroit with her husband and two sons.

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