What is a Crawl Space Vapor Barrier?
A crawl space vapor barrier is a durable liner installed over exposed soil to reduce the ground moisture evaporating into the crawl space air. Depending on the system installed, the liner may also extend up the foundation walls for added moisture protection.
Unlike loose-laid plastic sheeting, a professional vapor barrier uses durable, reinforced material with seams overlapped and sealed for more continuous coverage. For a more complete seal of the crawl space, crawl space encapsulation may be recommended. Vapor barriers can also be used in basements, where a basement wall vapor barrier helps control moisture entering through foundation walls.
Symptoms
Signs That Your [Target Location] Crawl Space Needs a Vapor Barrier
Moisture from exposed soil can make a crawl space damp and humid, though the signs aren’t always limited to the space beneath your home. You might notice changes in your living space or damage to the wood, insulation and other materials under your floors. Signs of excess crawl space moisture include:
- Musty smells
- Mold or mildew
- High humidity inside the home
- Wet, sagging insulation
- Rotting joists, beams and floor framing
- Bouncy or uneven floors
- A rise in pest activity
- Climbing heating and cooling costs
A professional inspection can determine whether ground moisture is contributing to the problem and whether a crawl space vapor barrier is the solution your home needs.
Crawl Space Vapor Barrier & Moisture Control Solutions
For Ground Moisture, Musty Odors and Moisture-Related Wood Damage
Reinforced Crawl Space Vapor Barrier
A reinforced crawl space vapor barrier creates a durable layer between your home and the exposed soil below it. Installed across the crawl space floor with seams overlapped and sealed, the liner keeps ground moisture from evaporating into the space and helps produce drier conditions that are less conducive to mold and wood rot.
For Humid Outside Air Entering the Crawl Space
Sealed Crawl Space Vent Covers & Access Doors
Ground moisture isn’t the only source of humidity below your home. Uncovered vents and poorly sealed access points can allow warm, humid outdoor air into the crawl space. Sealing the vents and installing a properly fitted crawl space access door helps cut down on outside air and moisture entry so your vapor barrier system works more effectively.
For Standing Water and Soaked Soil
Crawl Space Drainage Matting & Sump Pump
A vapor barrier controls water vapor, but it isn’t designed to solve standing water beneath your home. When groundwater or seepage is present, crawl space drainage can capture and direct water to a sump pump for removal. Drainage matting beneath the liner can also create space for water to move toward the drainage system.
For Humidity That Sticks Around After the Liner Is Installed
Crawl Space Dehumidifier
A vapor barrier limits the moisture coming from the ground, but humidity can linger in the crawl space air. If additional moisture control is needed, a crawl space dehumidifier removes excess water vapor from the air and automatically helps maintain more consistent humidity levels as conditions change.
How It Works
How Blackburn Foundation Repair Installs Your Crawl Space Vapor Barrier
Why Heavy-Duty Crawl Space Liners Matter
Crawl spaces are tough on thin plastic. Rough soil, rocks, foot traffic and service work can puncture or tear lightweight material over time. A durable, reinforced crawl space liner is made for these conditions, providing longer-lasting protection while helping keep ground moisture out of the crawl space.
What To Expect
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