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Crawl Space Vapor Barrier

Installing a vapor barrier is essential in sealing your crawl space, keeping your crawl space dry, and protecting your home from mold and rot.

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It is incredibly common for homeowners to install a crawl space vapor barrier as a part of a wider waterproofing process. These simple barriers are very important components in crawl space encapsulation and have a huge impact on the health and wellbeing of a property once they are installed, preventing dampness, humidity, and even pest infestation.  

Of course, getting the right crawl space vapor barrier is important to ensuring the best results. The thickness of a vapor barrier, any reinforcing materials added, and the presence or absence of anti-microbial properties all impact the results which a vapor barrier may provide. This is why calling a professional is crucial – they have the experience to ensure that the right vapor barrier is installed in every home. 

What is a Vapor Barrier?  

A vapor barrier is a waterproofing solution that prevents moisture from entering your property’s crawl space. All vapor barriers are made up of sheets of heavy gauge plastic, but there are some that are reinforced with anti-microbial properties and tear-resistant fibers to ensure a more robust result and higher levels of protection for a property. If you want to get the best results you should find a professional who can advise you as to what is best for your home.  

Why We Trust in the CrawlSeal™ Liner

If you’re interested in adding a crawl space vapor barrier to your home, you need to be sure that you are getting the right one – this is where a professional opinion can help. Here at Innovative Basement Authority, we favor the CrawlSeal™ crawl space vapor barrier. That’s because the CrawlSeal™ liner provides many benefits not available with some other crawl space vapor barriers.  


The CrawlSeal™ barrier uses 20-mil poly-reinforced plastic to make sure it’s as durable as possible. The barrier is waterproof, weatherproof, and mold-resistant, and it even comes with a longtime warranty. That means you’ll be sure to get benefits from the CrawlSeal™ barrier for years to come. Unlike thinner vapor barriers, our 20-mil barrier is far less likely to tear or puncture when someone needs to enter your crawl space, and is perfect for those who want to use their crawl space as a storage area.  


When you use a CrawlSeal™ vapor barrier, you can be certain that the barrier will keep out water, mold, and mildew, and make it more difficult for pests to get inside. That means your crawl space will stay dry, clean, and safe. You can use your crawl space for storage, allow someone into the crawl space to investigate it, or just be certain that your crawl space will stay clean. CrawlSeal™ is entirely non-permeable and will let no moisture pass into your home.  

Ease of Installation  

The Innovative Basement Authority team can install a CrawlSeal™ vapor barrier within just a few hours for most homes. The process is fairly quiet, non-invasive, and very simple. It’s one of the easiest crawl space vapor barriers to install. What’s more, our thick and durable liners are compatible with our other crawl space waterproofing and repair solutions. 

Resistance to Tears and Punctures  

Because of the blend of poly-reinforced plastic that a CrawlSeal™ 20-mil vapor barrier uses, you don’t have to worry about tears and punctures. Hardware store equivalents can be very thin and even flimsy, especially if you have a thinner crawl space vapor barrier, but with a CrawlSeal™ barrier, you’re unlikely to see damage from normal use. 


The longtime CrawlSeal™ guarantee ensures that you’ll be able to use your crawl space vapor barrier for many years to come. However, if you take care of your CrawlSeal™ barrier, you may never need to replace it. This is the best way to maximize your crawl space health, while being able to forget all about it and get on with the business of living! 

The Benefits of Vapor Barrier Installation

Vapor barrier installation is just one of the many encapsulation and waterproofing methods open to homeowners across Minnesota, North Dakota, South Dakota, and eastern Montana, but it is also one of the most effective. When installed as a part of a larger moisture control system, vapor barriers offer many benefits including:  

  • Prevention of standing water and dampness   

Vapor barriers prevent moisture from entering your home at all by creating a water retardant barrier which remains impenetrable as long as the barrier is properly installed and in good condition.  

  • Minimizes of the chances of mold and mildew formation   

The lower levels of humidity and dampness that a vapor barrier creates prevents the formation of substances like mold, mildew, and wood rot. This is crucial to maintaining the health and wellbeing of any crawl space.  

  • Preventing hospitable conditions for pest infestation   

Damp and humid environments are particularly attractive to many kinds of pests, especially if they have mold and mildew in them. Installing a quality vapor barrier will prevent pest-friendly conditions from forming, but will also make it harder for certain pests to get into the space in the first place.  

  • Prevention of musty odors   

Musty odors are part and parcel with dampness and humidity precisely because of the increased chances of mold formation and pest infestation. Installing a vapor barrier seriously reduces the likelihood of musty odors forming.  

  • Lowered energy consumption   

Humidity makes it hard for your HVAC system to function effectively. This is because humid air is hard to process, heat, and cool than arid air. As such, keeping humidity levels low by installing a vapor barrier makes a home more energy-efficient and could even lower energy costs in the long term.  

  • Controlled climate   

Humidity also causes temperature fluctuations, partly because of the strain it puts on the HVAC system in any property. A vapor barrier will therefore help to control the climate in your home – the effects of this will be maximized if a wider process of encapsulation is undertaken.  

All these benefits are in addition to the relatively quick, easy, and cost-effective installation process, which is minimally invasive. The extent of the benefits you see, however, depends on whether you fully waterproof your crawl space. Our complete moisture control system includes an interior drainage system, sump pump, dehumidifier, waterproof insulation, vapor barrier installation, and crawl space vent covers.  

The Installation Process  

The process of installing our moisture control system is incredibly quick and non-intrusive. If your home needs a full waterproofing system, the installation will look something like this: 

  • Covering Vents  

Perhaps the most important and straightforward thing you can do to protect your crawl space is to fit it with high-quality vent covers. Many older properties have crawl space vents because they were believed to minimize dampness. Now, of course, we know that this is not true and vent covers have become a must-have item. 

  • Removing Water Sources  

Once your vents have been covered our team will remove any standing water and address the sources of this dampness. This could mean installing an interior drainage system and a sump pump or addressing cracks in your walls and foundation. 

  • Structural Repairs  

If your property has suffered structural damage as a result of prolonged dampness, we will address these issues. For example, if you have damaged crawl space supports, we will install specialized jacks to ensure that your floors remain stable. 

  • Insulation and Encapsulation  

Once your crawl space is waterproof and structurally sound, we will install insulation on the walls and finish the encapsulation process with a vapor barrier. This will not only give you a dry and clean crawl space with a controlled climate, but it will also render your crawl space suitable for storage use. 

  • Dehumidifying  

If you still have minor dampness issues, we can also install a dehumidifier to keep your property dry and climate-controlled. We use self-draining, energy-efficient models to make sure that you get the best results without a huge cost.  

This process is dependent on your needs; if you do not need insulation or sump pump installation, we will not undertake this work. This means that every single homeowner gets a tailored solution that suits their property and needs exactly.  

Vapor Barrier


Installing a vapor barrier, whether individually or as a part of a wider waterproofing system, has the potential to save you money. Of course, the amount of money you can save depends on a number of factors.  

A Vapor Barrier Alone 

Installing a vapor barrier on its own will save you money in the long-term, but the savings will be limited for a number of reasons. The main way in which a vapor barrier will save you money is by lowering humidity. Humidity has a number of impacts on a property – the most active is the way in which it makes the air harder to condition. This means that a HVAC system uses more energy to get a less effective result, thereby increasing energy costs.  

Increased humidity also makes it more likely that exposed pipes will begin to rust and corrode, and will increase the rate of wear and tear experienced by all manner of household appliances. This means that installing a vapor barrier will not only lower energy bills, but will reduce the risk of avoidable breakdowns and the repair costs that they can incur.  

Full Encapsulation 

Installing a crawl space vapor barrier as a part of a wider process of encapsulation is a far more effective way to protect a home and save money for a number of reasons. Firstly, fully encapsulating a space will reduce humidity far more intensely than a vapor barrier ever could alone. This maximizes the savings on electricity bills and seriously reduces the chance of avoidable breakdowns and damage to appliances.  

A fully encapsulated crawl space will also be more energy efficient as a result of the insulation which is installed as a part of the encapsulation process. Insulation increases heat and cold retention, meaning that the climactic changes created by a properties HVAC system are maintained for longer. This means that the heating or air conditioning systems get a better result with less effort, thereby lowering energy costs in the same way that lower humidity does.  

Vapor barriers come in varying thicknesses which range from 6-mil to 20-mil, and each thickness has certain benefits and drawbacks to consider. It is generally accepted that vapor barriers under 10-mil in thickness are only effective for short-term use.  

Thin Barriers Tear More Easily 

While thin vapor barriers perform the same basic function as thicker barriers, it is generally accepted that they are less effective in this function than thicker barriers are. This is partly because of their delicate nature. Barriers under 10-mil in thickness are far less resistant to tearing and punctures as a result of pressure, pulling, and sharp objects, for example.  

Likewise, some thin vapor barriers may actually be permeable to a certain degree. This means that while they would prevent the majority of water and gaseous moisture from passing, thin vapor barriers might let small amounts of water into a home even if they are undamaged. Barriers under 10-mil may instead be considered vapor retarders, therefore, and will increase the risk of dampness, humidity, and other issues in your home.  

Thick and Reinforced Barriers Have Many Benefit  

Increasing thickness is not the only way to make a vapor barrier more effective, of course, but thicker barriers are generally more robust and impermeable. Barriers of 16-mil or more generally have a permeance rate of 0.0015 or less, which means they are considered fully impermeable by the standard of American building codes.  

The way in which vapor barriers are constructed also has an impact on their effectiveness, however. Barriers which are constructed with a woven pattern, or which have reinforcing fibers in them will be less prone to tearing and ripping, for example. Likewise, vapor barriers which have some sort of antimicrobial coating will contribute to a lower risk of fungal growths and formations inside a crawl space, even if moisture does somehow gain entry.  

A property’s crawl space is one of the areas that is most vulnerable to dampness and its associated issues. This is because crawl spaces tend not to benefit from the same protections as the rest of a property. Water and dampness have two main points of entry into a crawl space: exposed vents and cracks in the structure of your home.  

  • Uncovered Crawl Space Vents  

Crawl space vents were commonly installed in properties to manage dampness because it was believed that the increased airflow would prevent moisture buildup. These days, we know that is not true. These vents are the leading cause of dampness and humidity in a crawl space that is otherwise undamaged.  

This is partly because of how they let water into the space during periods of flooding and extreme weather, but also because they leave a crawl space more open to the elements. In winter, the temperature in a crawl space can plummet causing pipes to freeze and burst. In summer, however, the warm, humid air that enters a crawl space can cause condensation to form on cool surfaces, thereby creating dampness.  

  • Structural Damage  

If you do not have crawl space vents, or you have had them covered, and you still have issues with dampness, the most likely cause is damage to the structure of your home. Any damage that causes cracking in the walls or floor of your property’s crawl space acts as an entry point for moisture and can incubate dampness and humidity.  

The most common causes of structural damage are excessive hydrostatic pressure as a result of saturated soil or underground water sources and foundation damage. Your property’s foundation can be damaged in several ways, but it will usually come down to issues with the soil around your home. Expansive soil can damage a property as it shrinks and expands during climate changes.   

The Benefits of Working with Innovative Basement Authority 

We pour all our knowledge and passion into all our products; this is why we are confident that you will find our moisture control system to be superior to other systems. We only use the very best products in our encapsulation system, from durable, mold-resistant CrawSeal™ vapor barrier to energy-efficient dehumidifiers; we have fine-tuned our system to provide world-class results and we feel that this is exactly what we provide.  

For help with improving the health and safety of your crawl space and home, contact Innovative Basement Authority today to schedule a free inspection and repair quote

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