Pros and Cons of Crawl Space Encapsulation

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Crawl space encapsulation protects against moisture-related damage and odors, prevents mold, and stops pests entering the space. The inside environment is better controlled. Encapsulation is costly and needs proper installation, internal leaks go unseen, pressure balances change, and dehumidifiers are needed.

Crawl Space Encapsulation ProsCrawl Space Encapsulation Cons
It reduces structural damages caused by the prolonged presence of moisture and humidityEncapsulating a crawl space is quite expensive. Even if your crawl space is small and you are installing only the basic features, you might have to spend more than other sealing and waterproofing procedures require
Crawl space encapsulation removes existing molds and prevents new ones from growingInternal leaks can go unnoticed and lead to structural issues over time
Wiring and utility systems are protected against moistureIf not properly installed, it can lead to wasted time, effort, and, of course, capital
It prevents pests like termites and rodents from entering the crawl space and, by extension, your homeA change in air movement can affect existing HVAC systems
A more controlled indoor temperature, which improves comfortAdditional insulation like foundation wall insulation might be required
The absence of humidity in the air reduces the strain on heating and cooling systems. This allows you to achieve an agreeable temperature without consuming as much energy as you used toEncapsulation involves sealing the space so that outside air cannot come in. Thus, a dehumidifier might be required to control the humidity level in the space.  
It makes the crawl space unconducive for contaminants like mold and vermin, which release bad odors. The absence of moisture on surfaces also prevents damp smells from flowing into the living area 
The absence of humidity and bad odors improves the overall quality of air in your home

Pros of Crawl Space Encapsulation

pros of crawl space encapsulation

Reduce Damp-Related Structural Damage

The crawl space is vulnerable to moisture and humidity. Moisture is the major cause of damage in crawl spaces. It affects utility systems in the space as well as the overall structure of your home. 

The major sources of moisture in a crawl space include:

  • Plumbing leaks.
  • Seepage from soil and foundation walls.
  • Humidity.
  • Condensation.
  • Runoffs.
  • Improper ventilation of dryers and bathroom exhaust fans.

Even vented crawl spaces do not effectively get rid of water and if moisture is left in the area for a prolonged period, it can lead to any or all of the following:

  • Corrosion of plumbing features and metal elements.
  • Mold, mildew, and fungal growth.
  • Warping and buckling of the subflooring.
  • Cracks in the foundation.
  • Saging or sloping floors.
  • Damage to electrical, plumbing, gas line, HVAC and systems.
  • Serious structural damages.  

Crawl space encapsulation covers cracks that can draw in moisture, creates a moisture barrier to prevent seepage, establishes or confirms the presence of a functional drainage system, and sets up a dehumidifying system(s) to control the humidity level in the space.

This ultimately protects your home from the damages stated above or any other form of moisture-related damage. 

Avoid Mold Growth    

Damp environments are perfect breeding grounds for organisms like mold and mildew. The presence of mold in a crawl space isn’t just unattractive, it is also destructive and a source of discomfort. 

Molds grow on saturated surfaces. They are not always glaring and can grow in areas where they’re not easily detectable. If left alone, they eventually spread to other parts of the house.

A well-known consequence of mold is the musty odor it generates. Mold also produces toxic microscopic spores that can float into your living space and cause allergies and health complications to you and other people living in or visiting your home. 

The presence of mold in wood can also cause wood to rot. Encapsulating your crawl space not only gets rid of existing moisture and mold in the space, but it also controls the levels of humidity in your space, prevents moisture seepage, and, by extension, mold growth.

Since dry spaces are not conducive for mold, encapsulating your crawl space would limit their appearance in your crawl space.

Keep Wiring Safe From Moisture

In homes with one, the crawl space often houses the electrical and HVAC systems. The presence of moisture in the space can tamper with the functions of these utility systems. 

Damp crawl spaces can cause electrical wires and cables to oxidize. Oxidized wires can lead to issues like short-circuiting. 

If left for a prolonged period, mold can affect or completely damage wiring. Depending on the kind of damage, you might have to spend a lot of money on repairs. 

An encapsulated crawl space is dry and suitable to house various utility systems. Unlike an unsealed crawl space, an encapsulated space isn’t prone to moisture, thus you can rest easy knowing that you don’t have to worry about damages to your systems due to moisture and humidity. 

Prevent Pests From Entering the Crawl Space

Pests like insects and rodents often seek refuge in dark spaces. They enter the space through cracks or holes in the walls or floors and can find their way into your home as well.

Moisture soaks into porous materials and insects like termites love damp surfaces.

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The wood and the wooden structures in an unencapsulated crawl space would most likely be saturated. This makes for a perfect habitat for termites, which eat up wooden frames and flooring. 

Crawl space encapsulation seals up any medium that might serve as an entrance to these creatures. It also makes the space dry and uninhabitable for them. This saves you not only from the damages they might cause, but also prevents the inconvenience of trying to get rid of them from the crawl space or worse, your living area. 

Better Whole-House Temperature Control

A crawl space that is free of excess humidity and moisture impacts the temperature in the house positively. Encapsulation makes it easy to achieve a convenient temperature in your home, especially in houses built in cold climates.

Air-leaks can make it difficult to control the temperature in your home. An encapsulated crawl space is sealed against air leaks. So, you have one less thing to worry about, especially during the winter months.

A dry crawl space also improves the temperature of tile and hardwood floors and encapsulation keeps your crawl space dry at all times.  

An encapsulated crawl space isn’t affected by outside temperature. So, during summer, it allows cool air to flow into your house. It also reduces the high humidity that is common during the summer months. 

All these ultimately make your home a lot more comfortable. 

Increased Energy Efficiency

A large percentage of the air in your home flows up from the crawl space. This means that if the air in the crawl space is humid, then the air in the house would be humid as well. 

If humidity is present in the air, the HVAC system would have to work longer to achieve appropriate indoor conditions. 

Eliminating moisture in your crawl space can save you 15-20% of your heating and cooling cost.

Vented crawl spaces are open to outside air and are also prone to high humidity levels. So, if you encapsulate your crawl spaces, the absence of humidity and air leaks would result in less strain on HVAC systems, which would inadvertently reduce the amount of energy you consume. 

Less Chance of Bad Odors Entering Home

Air moves from the crawlspace to other parts of the house. This means that if your crawl space smells funky, that odor is going to spread to your home. 

A vented crawl space might feature odorous pollutants like mold, moisture, and vermin. Mold naturally releases a musty smell and nobody wants to have their indoor area smelling funky. Damp surfaces, especially damp or rotten wood, also produce an unappealing scent.

In the event that there is vermin or similar pests in your crawl space, the stench of their urine and feces would most likely flow into your home.

Crawl space encapsulation eliminates any of these if they are present and prevents them from entering or resurfacing in your crawl space through an airtight seal and a dehumidifying device.

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Improved Indoor Air Quality

I stated earlier that a large portion of the air in your house comes from the crawl space. This is an important factor, particularly if your crawl space houses your HVAC systems.

In this setting, the air in the crawl space, whether good or bad would circulate through your home via your heating and cooling systems.

As a result, it is crucial for the air in the crawl space to be healthy so that you can breathe easily and be free of health challenges that can arise due to bad air quality. This is important even if your HVAC unit isn’t housed in your crawl space because the air would still flow into your house from this lower region regardless.  

Crawl space encapsulation provides an air-tight barrier that prevents polluted outside air from entering your home. It also eliminates and prevents bad odors caused by damp surfaces, molds, and pests.

The absence of humidity, molds, and pests makes for an improvement in the quality of air in your home. 

A crawl space dehumidifier is usually set up during encapsulation. This ensures that the air and surfaces in the crawl space are free of humidity and moisture.  

Cons of Crawl Space Encapsulation

Cons of Crawl Space Encapsulation

Encapsulation Can Be Quite Costly

Encapsulating your crawl space doesn’t come cheap. HomeAdvisor estimates the cost of crawl space encapsulation to be between $1,500-$15,000. The average cost is recorded to be $5.500. 

The exact cost of encapsulating your crawl space is determined by the following factors:

  • The square footage of the crawl space.
  • The extent of damages in the space/condition of the space.
  • The scope of the project.
  • The type of material to be used.
  • The existing drainage system around the house.
  • Cost of labor. 

Crawl space encapsulation usually involves extensive procedures like:

  • Preparing the space to eliminate anything that might interfere with the encapsulation.
  • Sealing the crawl space against unwanted airflow and moisture.
  • Insulating the walls and floor.
  • Installing a dehumidifier to control moisture levels in the space.
  • Conditioning the space to get rid of existing moisture. 

As a result, you might have to contract a professional. This coupled with the expenses of the materials needed makes it a high-budget project. 

After the encapsulation system has been set up, you’d still have to spend money on maintenance and inspections at least twice a year to ensure that the space remains in prime condition. The maintenance cost would be dependent on the number of features used in the space. 

When the cost is considered, homeowners opt for alternatives that address the specific challenge(s) their crawl space is experiencing rather than going all out to encapsulate the space. 

Internal Crawl Space Leaks Can Go Unnoticed 

Encapsulated crawl spaces are often neglected except for when repair or maintenance work needs to be done. So, if there are issues that cannot be perceived from the floors above the space, they would most likely be neglected, and this can lead to a series of structural issues.

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In most homes, the crawl space houses the plumbing system. Water, sewer, and drainage pipes sometimes pass through the crawl space. In the event that any of these pipes starts to leak, it might go unnoticed until your next maintenance or inspection.  

Must Be Installed Properly

It is important that you make use of the right materials and that they are installed properly. So, unless you have proficient DIY skills, crawl space encapsulation needs to be performed by a professional. 

To fully enjoy the benefits of crawl space encapsulation, you need to follow the required procedures and not cut corners. For instance, homeowners that installed the new vapor barrier over the old one, instead of removing the old barrier before installing the new lining claim to experience odors similar to that of cat urine. 

Installing a vapor barrier instead of doing a full encapsulation is often an alternative that people consider and employ. However, they are not the same thing, as you can see from my article: Difference Between Encapsulation and Vapor Barrier.

Therefore, if you do not have the necessary skills, it’s best to hire an experienced contractor so that you do not waste your time, efforts, and resources. 

Section R408 of the International Residential Code describes the requirements for encapsulating a crawl space. However, city codes might have their unique requirements, so it’s best to check with your city laws before you proceed.  

Can Affect Your HVAC System

Unlike a vented crawl space, an encapsulated crawl space prevents outside air from entering your home. This restricts the amount of air that normally moves through your house. 

As a result, combustion-based heaters and furnaces will not have enough oxygen to function optimally. So, you might have to upgrade or replace your old HVAC system, which is designed to suit the previous level of air circulation and internal pressures.

Using an HVAC system that suits the level of air movement in your home ensures that the temperature in your house is consistent and comfortable. 

The process might also require an inspection of the ductwork to ascertain that there are no leaks that could tamper with the efficacy of the encapsulation.

In some cases, the ductwork might be completely moved out of the crawlspace.

Will Have to Install a Dehumidifier

Even after encapsulating your crawlspace, it is still prone to humidity. So, all encapsulated crawl spaces require a drying mechanism. 

Rather than spending on a dehumidifier, some homeowners keep their crawl space dry through the supply air method. This involves cutting a hole and installing a 4″ to 6″ vent into the supply plenum, so that dry air blows into your crawlspace while the HVAC system is running. 

However, this method, though a lot more affordable than a dehumidifier, isn’t very reliable.

So, homeowners, especially those in humid regions would have to employ a dedicated crawlspace dehumidifier. A dehumidifier responds to the humidity level in the crawl space, thus it runs whenever there is an increase in humidity.

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The cost of encapsulating a crawl space is already on the high side and a good-quality dehumidifier adds a reasonable sum to that amount. The average cost of a crawl space dehumidifier (you cannot use a regular one) ranges from $870 – $1800. 

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Extra Insulation May Be Required

Not all crawl spaces require additional insulation. However, depending on the state of your crawl space, additional procedures like foundation wall insulation might be required. 

The procedure involves covering the foundation walls with an R-value foam board. This results in more expenses, which might be a lot for people who are looking to save costs. 

If you’re using a contractor, the cost of insulating your foundation walls would most likely be added to the total cost of encapsulating the crawl space. 


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