Why Install a Vapor Barrier in Your Crawl Space?

[Polly Lieberman]

Vapor barriers, at their most basic, are created to protect your crawl space from excessive moisture. Damp air from muggy North Carolina springs and summers can cause and then accelerate mold and wood rot. Not only are these symptoms toxic to your living environment, but they will negatively affect the structural integrity of your home. Air with high moisture levels promotes a breeding ground for mold and mildew. Humidity, mold, mildew, and standing water also provide an attractive space for various bugs and critters to take root and nest. The odors and toxins from this nasty environment will rise into your living area—infecting it with nasty smells and potentially amplifying your allergies and asthma.

With an unsealed and unprotected crawl space comes the infiltration of Mother Nature. This means that temperatures from the outside could be pervading your home through your crawl space. While you may not notice this in your day-to-day life, the reality may sink in once you open your energy bill. Having your crawl space vapor barrier installed helps your HVAC system by keeping out exterior temperatures; this way, your heating and cooling systems won’t have to work as hard to keep you comfortable.

For many homes, the crawl space is where ductwork and piping are woven beneath the home, out of sight from the living space. When your crawl space has morphed into an unstable, moldy, and pest-infested environment, this could have major effects on your appliances. By stabilizing the temperature and moisture levels beneath your home, a vapor barrier can aid in preventing your pipes from bursting, pests from chewing through ductwork, and mold spores from traveling inside of your home.

Vapor barriers are one piece of a system that works to protect your crawl space. Having a crawl space dehumidifier, vent covers, and more solutions along with your vapor barrier can guarantee you a dry crawl space, year-round. As a result, the vapor barrier (along with locking out moisture) protects other solutions in your crawl space and allows everything to work in harmony. While there are many online tutorials for crawl space vapor barrier installations, nothing can match the quality that an expert installation provides. Many YouTube videos or listicles online give inaccurate advice on how best to install your crawl space vapor barriers. This includes things like stapling your plastic barrier down, venting your appliances into the crawl space, and even trapping moisture into the crawl space with poor-quality materials.

Many homeowners may be tempted to opt for a less expensive 6-mil thick plastic liner for their crawl space. These typically can’t cover all of the crawl space and can be easily punctured. Poor quality vapor barriers can amplify your crawl space issues by locking in moisture and causing more mold, wood rot, and pest infestations to grow. Having a high-quality vapor barrier with proper installation can ensure you enjoy its benefits for a long time.