If you’ve ever taken a peek into your crawlspace and noticed a sheet of plastic covering the ground, you might’ve wondered:
“Is that just there to keep me clean if I crawl in?”

Not even close.

In fact, that plastic, called a vapor barrier, plays a critical role in protecting your home from moisture damage. And if it’s missing, damaged, or poorly installed, your house could be vulnerable from the ground up.

What Is a Vapor Barrier in a Crawlspace?

A vapor barrier is a layer of plastic sheeting (usually 6-mil or thicker) installed on the ground of a crawlspace. Its main job is to prevent ground moisture from rising into the air beneath your home.

Here in Middle Tennessee, where humidity levels can spike, and clay soil traps moisture, that protection is especially important.

Why Vapor Barriers Matter in Tennessee Homes

While it may not seem like a big deal, excess moisture in a crawlspace can lead to major problems, including:

• Mold and mildew growth

• Musty indoor odors

• Wood rot and structural deterioration

• Higher humidity inside the home

• Increased pest activity (termites love moisture!)

A properly installed vapor barrier acts as a shield, reducing moisture intrusion and creating a healthier environment for the home above.

What a Proper Vapor Barrier Should Look Like

Unfortunately, many vapor barriers in Tennessee homes are poorly installed or incomplete. You might see torn plastic, unsealed edges, or open dirt areas that defeat the purpose entirely.

A quality vapor barrier installation should:

• Be sealed to the foundation walls

• Overlap and seal at seams

• Cover the entire crawlspace floor

• Be durable enough to resist tears and punctures

This creates a more impervious layer that keeps water vapor from ever reaching the crawlspace air.

When to Replace or Upgrade Your Vapor Barrier

If you inspect your crawlspace and see a vapor barrier that’s torn, bunched up, moldy, or not sealed to anything, it’s time for a fix.

At DILIGENT, we partner with our sister company, Riverside Environmental, to help homeowners in Nashville, Franklin, Murfreesboro, and beyond assess the condition of their crawlspaces and recommend the right solution. Whether that’s replacing the vapor barrier or going full crawlspace encapsulation for added protection.