Collection: Crawlspace Vapor Barrier

A crawlspace vapor barrier is a protective layer, usually made of plastic sheeting, installed over the ground in a crawl space. Its main purpose is to block moisture from the soil, helping to prevent mold, mildew, and structural damage.

Yes, in most cases a vapor barrier is highly recommended. It reduces moisture buildup, helps control humidity, and protects your home’s foundation and air quality.

To install a vapor barrier, clear the crawl space floor of debris, level the ground, and then roll out the vapor barrier sheets. Overlap the seams, tape them securely, and extend the barrier up the walls or piers for full coverage.

The most common thickness ranges from 6 to 20 mils. For long-lasting protection, especially in damp or heavy-use crawl spaces, a thicker barrier (10–20 mil) is generally recommended.

No, standing water should not be present under a vapor barrier. If water is pooling, it usually indicates drainage or groundwater issues that need to be fixed before installing the barrier.

When properly installed, a vapor barrier helps prevent mold growth by cutting off moisture. However, if there’s trapped water or poor installation, mold can still develop.

A high-quality vapor barrier can last 10–20 years or more, depending on thickness, material quality, and environmental conditions. Thicker barriers generally provide longer durability.