Frequently Asked Questions about Crawl Space Vapor Barriers

What Is a Crawl Space Vapor Barrier?

Vapor barriers will differ in appearance, depending on the type you want to invest in. In general, though, vapor barriers are broad and plastic-like in appearance. They’re often white in color as well.

A vapor barrier is designed to entirely seal your crawl space. As a result, they’ll also keep most gases out, only allowing for oxygen particles to pass through the barrier they form. If they can keep most gases out, then you can bet your boots they won’t let water or dampness into your crawl space either, regardless of how hard the Virginia rains come down.

Encapsulating your crawl space with a vapor barrier system is a permanent solution that will properly seal the area from the earth.

Do I Need a Crawl Space Vapor Barrier?

Vapor barriers are ideal waterproofing solutions for handling precipitation and keeping water out of your crawl space.

When Do I Need to Install a Vapor Barrier?

If you suspect your crawl space may be leaking, keep an eye out for the following signs:

• Cooler crawl space temperature: As water gathers in your crawl space, the temperature is going to start to drop. Why? Because water vapor draws the heat out of your home. The best way to keep an eye on the temperature of your crawl space is to keep a thermometer near the door. When you do, you’ll be able to make note of the temperature before and after a storm. If the temperature starts to drop after the rain passes through, you’ll want to keep an eye out for a leak.
• Water damage: While you don’t want to rely on your belongings to determine whether or not you have a leak, they’re often the surest sign of the leak’s existence and its severity. If your paper belongings are starting to curl up at the edges or your wooden belongings are starting to warp, you’ll need to get in touch with a contractor to preserve them while you can.
• Pests: If insects and animals can make their way into your home, so can water. Keep an eye out, then, for signs of an infestation. This can include droppings, nests, or damage done to your belongings. Unfortunately, if you have a crawl space infestation, you’re going to have to deal with both the infestation and the leak prior to installing a vapor barrier in your crawl space.
• Mold: When water starts to make its way into your crawl space, it’s going to feed any dormant mold particles that have settled there. As a result, a leaking crawl space can also result in a burst of old-growth. Head down into your crawl space, then, and make note of any mold clusters you can spot near your space’s joints. You’ll want to remove the clusters on your own or with the help of a professional before you start to waterproof the rest of the space.
• Bad smells: You can most frequently determine whether or not your crawl space is leaking by taking a good sniff of the space. After a rainstorm – or on your average day – your crawl space shouldn’t smell damp. If it does, you may have a leak on your hands. You’ll also want to get in touch with a contractor if you frequently notice a smell like rotting coming from your crawl space. It may be coming from an infestation, your belongings rotting, or something else – but it’s never good.

What’s the Best Vapor Barrier to Get?

When it comes to which vapor barriers are best, you have some options. There are many types of vapor barriers for many different uses. However, the thinnest vapor barrier on the market for crawl spaces tends to be a 6-mil barrier, and the thickest is a 20-mil vapor barrier or above.

Option #1: Off-the Shelf Vapor Barrier (6–12 Mils)

Vapor barriers come in a variety of different thickness. Vapor barrier thickness is measured in “mils.” Rather than being short for “millimeter,” one mil is one-thousandth of an inch. Because this is such a small measurement, it’s easy to see why even these seemingly tiny differences make such a big impact.

Option #2: The Industry Standard (12–20 Mils)

What’s the industry standard for vapor barriers? That’s a tough question to answer. Again, it somewhat depends on who you’re asking; the person you’re asking will often claim it’s whatever they use.

Some contractors use 12-mil barriers. The 12-mil barrier is also very popular among DIY homeowners who want to save money. That’s because the 12-mil barrier is much cheaper than the 20-mil barrier.

Although you’ll still see 12-mil barriers in use at times, the industry seems to be moving toward embracing the 20-mil barrier as the standard. It’s certainly the premium standard among high-quality contractors like JES. 

The Best Choice: CrawlSeal™ 20-Mil Vapor Barrier from JES!

If you’re looking for a crawl space encapsulation that actually encapsulates, you’re going to want to choose a 20-mil liner. But you’re also going to want a professional to install it.

At JES Foundation Repair, we use our very own proprietary vapor barrier design—the CrawlSeal™ Vapor Barrier. It’s a 20-mil liner that we install professionally and FAST in your crawl space to protect against moisture damage. You can learn more about it on our Crawl Space Vapor Barrier Installation page.

Talk to a JES expert today about utilizing CrawlSeal to keep water vapor out of your crawl space.

How Is a Vapor Barrier Installed?

In the era of DIY, you may consider installing a vapor barrier on your own. If you’ve never done so before, though, you may want to seek out the guidance of a professional.

In general, the process of installing a vapor barrier involves the following steps:

• Clear out your crawl space.
• Find any old or new leaks.
• Seal off your leaks.
• Take out damaged insulation.
• Put up your new vapor barrier.

Don’t let the Virginia rains keep you from using your crawl space. Talk to your local contractor about installing a crawl space vapor barrier.