Wondering if there are any negatives to crawl space encapsulation? If so, stick around because we’re going to talk about that in this article. We’re also going to go over why crawl spaces get wet, why you don’t want moisture in a crawl space, and more.
Why You Don’t Want Moisture In A Crawl Space
You don’t want moisture in your home’s crawl space because it causes a lot of problems including mold growth, wood rot, and wood-eating pests. All of these can eventually affect the structural integrity of the wooden structures in the crawl space. Since the crawl space holds up your home – literally – you want it to be as structurally sound as possible.
Another reason you don’t want moisture in the crawl space is a phenomenon known as the stack effect. The stack effect causes air from the crawl space to flow up into the home’s living area. Therefore, if your crawl space is full of mold, the air flowing into your home will be as well. This could cause allergies and other respiratory problems for anyone living in the home.
Finally, a wet crawl space means the air flowing up into your home will be humid. Since humid air is harder to heat and cool, this reduces energy efficiency in your home.
Why Crawl Spaces Get Wet
Crawl spaces get wet for various reasons. However, the most common reasons are:
- Leaky plumbing – Homeowners like crawl space foundations because they offer easy access to the home’s electrical wiring and plumbing. However, a water or drainage pipe can be a source of moisture in a crawl space if it starts leaking.
- Open crawl space vents – It was once thought that crawl space vents would keep the crawl space dry by allowing air to flow through the area. However, it didn’t turn out that way. Open crawl space vents actually allow warm, humid air to enter the crawl space and condense on cooler surfaces creating moisture.
- High water table – A high water table will make the soil wetter than normal, contributing to moisture in the crawl space.
- Poor drainage around the foundation – Poor drainage around the foundation is probably the number one cause of crawl space moisture. Fortunately, it’s easy to fix via a drain tile system. We’ll talk more about drain tile systems in just a bit.
For more information, see Is crawl space encapsulation worth it.
Crawl Space Encapsulation Plus A Drain Tile System – The Best Way To Keep A Crawl Space Dry
If you want a clean, dry crawl space that you can use to store things like tools and holiday decorations, crawl space encapsulation along with a drain tile system is the way to go.
Drain Tile System
A drain tile system keeps the ground dry around the foundation by preventing excess moisture from building up in the soil. There are two types of drain tile systems, exterior and interior.
Exterior drain tile system
An exterior drain tile system is installed around the outside perimeter of the foundation at the footing level. The installation procedure is as follows:
- The soil is excavated down to the footing.
- A shallow trench is dug and then lined with gravel.
- A perforated drainage pipe is placed on top of the gravel and then covered with more gravel.
- The excavated soil is replaced.
Excess moisture in the soil will now flow into the drainage pipe and toward the sump pit. Once the water in the pit reaches a certain level, the sump pump will turn on and expel the water away from the foundation.
Interior drain tile system
An interior drain tile system is installed around the inside perimeter of a basement or crawl space. If the drain tile system is installed in a basement, the floor will need to be broken up first. Here’s the general installation procedure:
- A shallow trench is dug around the inside perimeter of the basement or crawl space.
- After the trench is lined with gravel, a drainage pipe is placed into the trench and covered with more gravel.
- If the basement is going to be finished, the slab will be replaced.
Now, any excess moisture in the soil will find its way into the drainage pipe and get directed toward the sump pit. Once the pit fills with water, a sump pump will turn on and release the water away from the foundation.
For more information about drain tile systems see, How Does A Drain Tile System Work?
Crawl Space Encapsulation
After the drain tile system – either exterior or interior – has been installed, the next step is crawl space encapsulation. Crawl space encapsulation involves sealing the vents and covering the floor and walls of the crawl space with a thick, plastic vapor-retarding barrier. We recommend installing a dehumidifier as well in the crawl space to ensure the humidity stays low. For more information on crawl space encapsulation see, Don’t Install A Crawl Space Dehumidifier Without Encapsulation.
Negatives To Crawl Space Encapsulation
The only real negatives to crawl space encapsulation are the cost of installation and the cost of maintaining the dehumidifier, the sump pit, and the sump pump.
Other Ways To Keep Your Crawl Space Dry
Since excess moisture in the soil around the foundation is the most common cause of moisture in a crawl space, you can go a long way toward preventing crawl space moisture by simply controlling groundwater around the foundation. A drain tile system is the best way to do this. However, here are some other ways:
- Clean your gutters regularly to prevent water from spilling over the side of your house and soaking the ground around the foundation.
- If necessary, install downspout extensions so that runoff gets released at least four feet from the foundation.
- Don’t plant shrubs, flowers, small trees, etc. next to the house. When you water them you’ll be adding water to the soil around the foundation and this is what you’re trying to avoid.
- If necessary, regrade your yard so it slopes away from the foundation. This prevents water from draining toward the foundation.
If you’re thinking about crawl space encapsulation, contact us today to schedule a crawl space evaluation. We serve areas in Nebraska, Iowa, Kansas, and Missouri. See our Service Area page for more information.