Skip to Main Content
torn vapor barrier in crawl space

Ineffective Vapor Barrier

A strong vapor barrier is essential in encapsulating your crawl space. If your vapor barrier isn't properly installed or it isn't made of a quality material, you could be facing problems like mold, excessive moisture and humidity, and high electric bills. Learn more about why you need to protect this sensitive area under your home.

Schedule Free Inspection
torn vapor barrier in crawl space

An ineffective crawl space vapor barrier can be a nightmare to deal with. You know you need a vapor barrier in your home for maximum efficiency, but why isn’t the vapor barrier working? What’s wrong with the one you have already? Here’s how you can fix these ineffective crawl space vapor barrier problems you’re probably already dealing with.

Does Your Vapor Barrier Look Like This?

Crawl space issues related to an ineffective vapor barrier are fairly common, especially in homes that tend to have older crawl spaces. JES can help you with your crawl space issues to fix them completely.

Crawl Space Vapor Barriers

Learn more about problems with crawl space vapor barriers, what caused these issues, and your options for fixing them.

There are a few questions that can quickly showcase whether you have a crawl space vapor barrier issue. If your answer to any of these questions is “Yes,” you should schedule an inspection as soon as possible.

Is the Crawl Space Vapor Barrier Torn? 

The first question you should ask is whether you can see any tears in the crawl space vapor barrier. This is especially common in very thin vapor barriers, like the required minimum 6-mil vapor barrier, because it can tear as easily as a plastic bag in many cases. Though it’s the minimum requirement, you should never choose a 6-mil vapor barrier.

If you see any tears in the barrier, the barrier is obviously no longer working. Water and air will find its way through any crack, no matter how slim. Even if you don’t see any tears in the barrier, it’s possible that there are tears you simply can’t see. Keep asking questions to see whether you’re having any other crawl space vapor barrier problems.

Are There Puddles on the Vapor Barrier? 

Next, ask whether you can see any puddles of water on the vapor barrier. If you can see physical puddles of water, it means there’s some kind of issue with the vapor barrier that’s permitting water to collect. That inherently means your vapor barrier isn’t working properly because it’s not keeping water out.

Water vapor barriers can form a great place for water to collect if it’s not working properly. The plastic may form small pockets that are easy for water to collect in. However, that just means it’s easier for you to see if your vapor barrier is broken in some way or another because you’ll note these recesses of water.

Do You Still Have a Problem with High Indoor Humidity? 

This is perhaps the most telling sign you’re dealing with a vapor barrier issue. If you have a vapor barrier in your crawl space, but you’re still dealing with high indoor humidity, at least one thing is true: either the vapor barrier is not effective or there’s another entrance for water in your crawl space somewhere, likely in the walls.

High indoor humidity can happen if you have an effective water vapor barrier. However, it typically won’t happen at a rate that’s higher than the outside humidity if you have effective crawl space encapsulation. Regardless of the reason for the high indoor humidity, it’s a good idea to get a crawl space repair expert to make sure the vapor barrier isn’t the issue.

Has It Been More Than One Year Since Your Last Inspection?  

It’s a good idea to have an inspection every year on your crawl space, including your crawl space vapor barrier. You probably wouldn’t drive a car that hadn’t been inspected in the proper amount of time, so why would you have a crawl space vapor barrier that you haven’t paid enough attention to every year since you’ve first installed it?

Many things can cause problems for crawl space vapor barriers, from the constant water vapor pressing on it to potential issues with pests, insects and mold. Ideally, the vapor barrier should be able to protect against it, especially if it’s a super-thick barrier. However, it’s possible that you could have an issue, and that’s the best argument for a yearly inspection.

There are many reasons a crawl space barrier might not work in your home. These are the most common reasons you might find your crawl space barrier is no longer working or seems to have never worked.

Too Thin 

If you have a crawl space barrier that’s too thin, you’re not going to get the right amount of function from the barrier. Sure, the IRC minimum requirement for vapor barrier thickness is 6-mil, but are you really comfortable with utilizing the minimum requirement when you could instead go with a crawl space vapor barrier that’s thicker and more effective?

The thin nature of the crawl space vapor barrier will necessarily have an impact on its efficacy. A thinner crawl space vapor barrier will be more likely to tear, more likely to allow moisture through, and less likely to encapsulate your crawl space effectively. It’s much better to choose a thicker alternative like the 20-mil CrawlSeal crawl space vapor barrier instead.

Installed Incorrectly 

Whether you tried to install the crawl space yourself or you just used a crawl space repair “expert” that didn’t really know what they were doing, it’s entirely possible that your crawl space vapor barrier has an incorrect installation. If your crawl space vapor barrier was installed incorrectly, there’s a very high chance it’s not really doing its job in keeping out water vapor.

The only way to fix this problem is to tear out the crawl space vapor barrier and start from scratch. More than likely, the barrier already has tears, debris, water, and other terrible things under and on top of it. This is a great reason to invest in a high-quality crawl space repair expert from the very beginning; installing things correctly can make it much easier to handle in the future.

Too Much Already-Existing Humidity 

This is typically a problem if you installed a crawl space vapor barrier without really thinking about the situation in your crawl space. For example, if you already had an extremely damp crawl space, chances are that crawl space will be damp with or without a crawl space vapor barrier, if you don’t do anything extra to fix that barrier.

For the most part, you can fix this with a crawl space dehumidifier. However, be careful; if you’ve waited too long, your crawl space may have condensation and mold in it already, which are both problem signs you need to address directly. Ideally, you should put a dehumidifier in as soon as you install a vapor barrier in the crawl space.

Debris on the Crawl Space Ground 

Some people, to cut corners, may choose not to remove debris on the crawl space ground before they lay down the crawl space vapor barrier. Although this may make the crawl space vapor barrier more affordable at the time, it’s also not a great option for saving money because it will invariably have a poor effect on the crawl space vapor barrier you’ve just applied.

Many times, this debris can be the cause of tears in the crawl space. Even if the debris is just the remains of a previous crawl space that broke down, it doesn’t matter. The debris will inherently change how the crawl space vapor barrier falls, which will cause additional stress on the barrier as a whole and may impact the lifespan of the barrier.

How can you fix your crawl space vapor barrier? Consider some of these purported “fixes,” some of which won’t work and will just make your problems worse.

Sand Floors 

There is a rumor that if you lay sand down on your crawl space, you won’t have to deal with crawl space vapor barrier. Many people believe that the sand will “absorb” the moisture, making it so that the moisture isn’t a problem in your crawl space as a whole. In reality, all you’re doing is making a giant mess and making it less likely that you’ll fix your problem.

If you do add sand to the floor of your crawl space, that just means someone will have to remove the sand before laying down a crawl space vapor barrier in the future. Try to avoid the temptation to add sand to your floors in the hope that it will make your crawl space vapor barrier more effective, because it actually won’t make a difference.

Another Cheap Crawl Space Vapor Barrier 

Some people, despite having already invested in a cheap and unusable crawl space vapor barrier, proceed to then try another cheap crawl space vapor barrier the second time. This might be because they think it’s normal to have to replace crawl space vapor barriers regularly or just because they want to save money.

Regardless of the reason, installing more cheap crawl space vapor barriers just won’t work. No matter how many you install, these cheap 6-mil crawl space vapor barriers will invariably tear and break down over time. The only way to fix this problem is by installing a high-quality vapor barrier instead, which won’t break down in the same way. 

DIY Vapor Barrier Installation  

Some people believe they’ll be able to do a DIY vapor barrier to make their vapor barrier concerns go away. Instead of hiring an experienced crawl space repair expert to install a vapor barrier, they just purchase their own from an expert’s supply store, then try to install it in their own crawl space. As any expert can tell you, this is a difficult job, and it’s not one the DIY expert can do.

Invariably, a DIY crawl space vapor barrier installation can go wrong in many ways. Whether it’s not covering the entire crawl space, opening a tear in the crawl space vapor barrier, not putting the crawl space vapor barrier high enough, or some other concern, this DIY crawl space vapor barrier installation will not go well.

A Custom, Economical Solution for Your Home 

Of all these potential fixes, only this one has any actual weight behind it. When you’re looking for ways to install a crawl space vapor barrier, it’s important that you pay attention to your home’s unique needs. That’s why it’s so important that you rely on a crawl space repair expert who knows how to install and take care of crawl space vapor barriers.

Devising a custom solution to your home is crucial. No two homes are exactly the same or have exactly the same needs. Even so-called “cookie-cutter houses” all rest in slightly different locations, with the possibility of slight variance between how the homes’ foundations were prepared. That’s why you need a crawl space repair expert who knows how to take into account your needs and wishes when it comes to your crawl space.

Relying on the Experts to Help You Solve Your Problems

At the end of the day, it’s a good idea to rely on the experts from the get-go. The last thing you want is to spend a lot of time, money, and energy in attempting to fix a problem that you may not be able to accomplish a useful fix for. Your best bet is to make sure you get your fix from a reputable crawl space repair expert.

Don’t waste your time and money pursuing fixes that might not actually fix anything. Instead, consider scheduling an appointment with a JES crawl space repair expert. You’ll be able to explain your problem and give the crawl space repair expert more information about what’s going on. After an inspection, this expert will give you a recommendation and an idea of what to do.


Schedule your free inspection
Schedule your free inspection
encapsulate your crawl space

Publish Date:

Last Modified Date:

Service Areas


8361 Town Center Ct
Nottingham, MD 21236


311 Central Rd.
Suite 2-02
Fredericksburg, VA 22401

Hampton Roads & NE NC

2569 Quality Ct
Virginia Beach, VA 23454

Northern VA & DC

7940 Gainsford Ct.
Bristow, VA 20136


309 Quarles Rd
Ashland, VA 23005

Southwest Virginia / Roanoke

2033 Cook Dr.
Salem, VA 24153

Western Virginia

456 Old Courthouse Rd
Appomattox, VA 24522


45 W Boscawen St,
Winchester, VA 22601