Crawlspace Encapsulation: What You Should Know!

Crawlspace Encapsulation: What You Should Know!

Why Does My Crawlspace Need A Vapor Barrier?

Why Does My Crawlspace Need A Vapor Barrier?
Why Does My Crawlspace Need A Vapor Barrier?

One of the most common problems we encounter is mold in crawlspaces. Continuing on with our series of articles on crawlspaces the purpose of this article is two fold.

First, we will answer the most common questions asked about crawlspaces.

Second, we will explain why crawlspace encapsulation is so important by listing and explaining the top 5 reasons your crawlspace needs a vapor barrier.

FAQ About Crawlspaces!

FAQ About Crawlspaces!
FAQ About Crawlspaces!

If you look into your crawlspace, you may notice standing water, moldy insulation, or a bad smell. Listed below are the top questions we encounter about crawlspaces.

Why Do Crawlspaces Get Wet?

Your crawlspace could be wet for several reasons:

  1. Cracks in the foundation or walls allow water and moisture to enter your crawlspace.
  2. Improper ventilation can allow moisture in.
  3. Poor drainage systems also allow moisture and water in.
  4. Poor maintenance and not sealing the dirt floor is another common reason your crawlspace is wet or damp.

Why Are Wet Crawlspaces A Problem?

There are two key problems caused by wet or damp crawlspaces.

First, if your crawlspace has standing water or is damp, this will encourage the growth of mold and mildew.

Second, the excess moisture and mold will also cause wood rot and structural deterioration.

Do Vents Keep My Crawlspace Dry?


Unfortunately, vents will not keep your crawlspace dry.

Moisture and humidity can still accumulate in your crawlspace, which in turn will lead to mold and wood rot.

In addition, often times the air flow is impeded when the vents get blocked by plants or other object outside the vent. When this occurs, water that collects around the home or drips down the exterior walls can enter your crawlspace creating moisture problems.

Will The Air In My Crawlspace Enter My Home?


A large percentage of your home’s air, 40% or more, comes from your crawlspace.

Air in your crawlspace seeps up into your home through the floors, and around heating and air ducts.

The air quality of your crawlspace can have a negative impact on your home if there is excess moisture and mold.

Common health issues caused by poor crawlspace air include headaches, fevers, and respiratory problems.

What Can I Do To Keep My Crawlspace Dry?

If your crawlspace is wet, the following steps must be taken.

  1. All moisture and water must be eliminated.
  2. Wet insulation and standing water needs to be removed.
  3. The ventilation system must be inspected to ensure it is working efficiently. If not, it needs to be fixed.
  4. The next step is to figure out why you have a moisture problem in the crawlspace by finding and fixing any cracks, holes, leaks, or damage to the walls, ceiling, and floors.
  5. The final step is to seal up the damaged areas and install fresh insulation, and most importantly install vapor barrier, which is explained in greater detail below.

Now that you have answers to the most common questions we encounter about crawlspaces, the remainder of this article will explain why the installation of a vapor barrier is so important.

Top 5 Reasons Your Crawlspace Needs A Vapor Barrier!

Top 5 Reasons Your Crawlspace Needs A Vapor Barrier!
Top 5 Reasons Your Crawlspace Needs A Vapor Barrier!

Keeps Moisture in the Soil!

According to the EPA, a vapor barrier will keep your home drier and is especially recommended for older homes to control dampness. In areas where humidity is an issue, your crawlspace likely has moisture and damp issues and a vapor barrier will help keep the moisture down because it will prevent moisture from escaping from the soil.

Installed correctly and spread uniformly across the soil and the the walls of your crawlspace, the vapor barrier creates a barrier between moisture and your home.

Prevents Ductwork from Rusting and Corroding

Most homes with crawlspaces have ductwork running underneath their home, and many have their HVAC system installed under the house as well.

It is important to keep moisture at a minimum to prevent metal from rusting and corroding.

Prevents Wiring Hazards

Many crawlspaces also have wiring. Water and electricity do not mix well. Accumulation of excess moisture is a potential fire hazard and could create an unsafe environment for anyone that enters the crawlspace.

Keeps Your Home Dry

Since excess moisture in your crawlspace can enter your home through the floor boards, keeping the moisture to a minimum will also help maintain moisture levels in your home.

In addition to a damp free home, a vapor barrier will also reduce your utility bills because your air conditioner will operate more efficiently.

The risk of excess dampness and moisture in your home is mold. If your crawlspace is wet and that moisture enters your home, you will not only have mold problems in the crawlspace but your home.

As mentioned earlier, mold can cause health problems; moisture control is imperative in both your home and crawlspace.

Keeps Your Crawlspace Clean

Your crawlspace is an area of your home that you can potentially use for storage. In order to ensure that your crawlspace is a safe and clean environment, a vapor barrier will reduce moisture and also keep the area clean and less inhabitable for rodents and insects.

If you plan to use your crawlspace for other uses, such as storage, we recommend that you use a stronger and thicker barrier.

The most important role that a vapor barrier plays is keeping the moisture in the soil. At the same time, it will help maintain a cleaner and safer environment for you, should you choose to use it for storage or other uses.

Got Crawlspace Questions?

Got Crawlspace Questions?
Got Crawlspace Questions?

If you have questions about your crawlspace, please give us a call, 703-897-7121 or send us an e-mail. We look forward to serving you! 🙂

Top 5 Ways Your Crawlspace Affects Your Home

Top 5 Ways Your Crawlspace Affects Your Home!
Top 5 Ways Your Crawlspace Affects Your Home!

1 Comment

  • It’s really interesting that 40% or more of the air in your house comes from the crawlspace. I have a crawlspace that hasn’t had anything special done to it, it’s basically a hole with a tarp on the bottom. Maybe I should look at getting it encapsulated so that I don’t have to worry about things like moisture.

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