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Crawl Space Vapor Barrier

Having your crawl space properly sealed with a durable vapor barrier is important in maintaining the health and safety of your crawl space and home. Learn more about the CrawlSeal™ vapor barrier installed by JES and how it benefits your home.

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crawl space beforecrawl space after encapsulation

Crawl Space Vapor Barrier – Why?

A damp crawl space is a breeding ground for mold, mildew, wood-rotting fungus, insects, and rodents, which is why it’s vital to encapsulate your crawl space using a proper vapor barrier. This picture shows a thin, plastic vapor barrier, which was easily torn. The goal and objective of encapsulation is to protect or isolate your home from the water or moisture vapors that come from the earth. This, in essence, also protects the floor joists in your crawl space from mold and the air quality in your home. 

Did you know over 50% of the air you breathe on your first floor comes from your crawl space?

Is your crawl space safe? Find out now by letting JES inspect your crawl space for free!

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encapsulated crawl space

CrawlSeal™ Encapsulation System is the Protection You Need

The JES CrawlSeal™ Encapsulation System eliminates moisture in your crawl space, discourages insects and rodents, and makes your home a healthier place to live. It also protects the structural integrity of your home and can reduce energy costs from 15 – 25%!

Is your crawl space safe? Find out now by letting JES inspect your crawl space for free! Sign up today! 


Benefits of the CrawlSeal™ Vapor Barrier

  • Thickest vapor barrier available
  • 25-year warranty
  • Cuts energy costs by 15-25%
  • Creates additional safe storage space

Crawl Space Vapor Barrier FAQs

A crawl space vapor barrier is highly encouraged if you have a dirt crawl space. Here's everything you need to know about your crawl space vapor barrier.

Mold tends to flourish in your home when it has ready access to warmth, moisture, and darkness. While you can’t always eliminate these elements from your crawl space, you can still work to get ahead of mold growth throughout your home.  

For starters, note that mold spores do not enter your home through the same cracks and leaks that allow excess moisture indoors. Instead, mold spores come into your home via wayward air currents. If you want to work to avoid mold growths in your home, then it is in your best interest to inspect your HVAC unit on a regular basis and to ensure that your filters are clean.  

If you don’t have experience identifying mold on a consistent basis, it may not be easy for you to determine what kind of mold is plaguing your crawl space. During a personal inspection, however, you can keep a wary eye out for clusters of odd growths. Trust your nose, too, and react accordingly if a smell in your crawl space seems off. You’ll want to reach out to area professionals for guidance as soon as you can if you believe you have mold growing in your crawl space. 

Preventing Mold Growth in Your Crawl Space  

When it comes to the care and keeping of your crawl space, matters can become tricky. As mentioned, mold loves moisture, heat, and darkness. While in the depths of winter you may be reluctant to turn off your heat, you can still contend with the moisture that may be making its way into your home. By preemptively waterproofing your crawl space, you can prevent water from entering that space and, in turn, stall mold growth.  

Vapor barriers, in particular, are especially dense sheets of plastic-like materials you can establish along a single wall or all across the room of your choosing. The density of these waterproofing measures prevents both gas and water vapor from entering your home. As such, vapor barriers can work to prevent the growth of mold in your home, though they are not actively mold resistant. There are some brands you might invest in that do work to repel the mold spores that might take root in your home, but your basic vapor barrier rather eliminates the moisture that allows mold to flourish.  

How Thick Should a Vapor Barrier be in a Crawl Space?  

A vapor barrier’s density sets it apart from other types of plastic insulation you can use to protect your crawl space from damage. However, vapor barriers also need to have a weight to them if you want them to keep moisture out of your home. The thicker your vapor barrier is, in short, the better it should be able to keep water out of your space.  

To create an appropriately insulated space, your vapor barrier should be a minimum of 6-mil thick. That may not seem like a substantial thickness, but in providing your vapor barrier with that weight, you ensure that both gas and water particles will face significant obstacles when trying to enter your home.  

When to Exceed Expectations with Your Vapor Barrier  

Of course, your vapor should meet this 6-mil requirement at a minimum to serve as a protective measure within your home. If you’re looking for more durable materials, then it is in your best interest to discuss thicker vapor barriers with the professionals in your area. Some of the thickest vapor barriers can be up to 20-mil thick.  

If you’re concerned about the cost of a thicker vapor barrier, or if you want to explore what other waterproofing options might pair well with a thinner vapor barrier, you can work with the professional contractors in your area to determine what the needs of your home look like. During a home inspection, you can discuss the problems you’ve had with seepage or high levels of humidity in the past and, in turn, determine whether traditional or custom vapor barriers can help you restore your home’s value.  

A vapor barrier’s density sets it apart from other types of plastic insulation you can use to protect your crawl space from damage. However, vapor barriers also need to have a weight to them if you want them to keep moisture out of your home. The thicker your vapor barrier is, in short, the better it should be able to keep water out of your space. 

To create an appropriately insulated space, your vapor barrier should be a minimum of 6-mil thick. That may not seem like a substantial thickness, but in providing your vapor barrier with that weight, you ensure that both gas and water particles will face significant obstacles when trying to enter your home. 

When to Exceed Expectations with Your Vapor Barrier 

Of course, your vapor should meet this 6-mil requirement at a minimum to serve as a protective measure within your home. If you’re looking for more durable materials, then it is in your best interest to discuss thicker vapor barriers with the professionals in your area. Some of the thickest vapor barriers can be up to 20-mil thick. 

If you’re concerned about the cost of a thicker vapor barrier, or if you want to explore what other waterproofing options might pair well with a thinner vapor barrier, you can work with the professional engineers in your area to determine what the needs of your home look like. During a home inspection, you can discuss the problems you’ve had with seepage or high levels of humidity in the past and, in turn, determine whether or not traditional or custom vapor barriers can help you restore your home’s value.

As opposed to a basement where you could choose to install a vapor barrier on one wall, that is not advised in a crawl space. So, where should you install a vapor barrier for the greatest effect?  

Installing a Vapor Barrier in Your Home 

Under no circumstances should you install a vapor barrier on a single wall in a space as contained as your crawl space. There’s too much potential for damage in one part of your crawl space to move to another wall. With that in mind, installing a vapor barrier in your crawl space actually requires you to encapsulate the whole of your space. 

Crawl space encapsulation sees the professionals in your area wrap your crawl space floor and walls in a vapor barrier. While you’ll still be able to enter your space, should you choose to do so, virtually no part of the space will be free of the thick, plastic-like material that professionals use to keep moisture out of your home. You can work with area professionals, of course, to ensure that your utilities and other materials are protected as best as they are able, but the encapsulation process is meant to create a seal within your space that is extremely difficult to breach. 

To encapsulate your crawl space, the professionals in your area will clear out any moisture that may have plagued your crawl space. Then they’ll install any necessary preliminary waterproofing measures, including interior drainage systems or insulation in your walls. Only once your crawl space is perfectly dry will professionals encapsulate it. They may simultaneously choose to install a sump pump or a non-commercial dehumidifier, depending on the conditions that have plagued your space in the past. 

Alternative Means of Home Waterproofing  

It is in your best interest to install a vapor barrier near where water or moisture may be getting into your home. However, if you are concerned about the appearance of your home and the impact of a vapor barrier aesthetically, you can work with a professional contractor to determine what additional waterproofing measures might help compensate for the areas that a vapor barrier can’t (or won’t) be placed. Some of the most effective waterproofing measures to pair with a vapor barrier include:  

  • Interior drainage systems  
  • Sump pumps  
  • Dehumidifiers   

Don’t hesitate to ask area professionals if stacking your home waterproofing measures might serve your home well. The investment is all the more worth it to have these measures available to you if they prevent the kind of seepage or flooding that you’ve dealt with in the past. 

JES Can Help You With Your Crawl Space Repairs!

Not sure what’s going on in your crawl space or how to start the repair process? We’re here to help you find the perfect solution for your home, and find out the source of your crawl space problems.

Requesting your free inspection takes 30 seconds, and you can download your Free Homeowner’s Guide to Crawl Space Repair immediately!

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