You’ve probably grown up knowing homes around your neighborhood have a space underneath them that homeowners can crawl around in. You may never have really questioned why they’re there or what purpose they serve. Let’s delve into the world of crawl space foundations so you can understand them better.
What Is a Crawl Space?
A crawl space refers to a below-grade area or the space between your house and the ground. It’s usually around 1½ feet to 3 feet high and in most cases has a dirt floor. The FHA requires crawl spaces to be at least 18 inches high.
Crawl space foundations are built the same way as normal basements; they’re just smaller. Their construction involves digging trenches below the frost line and pouring concrete uniformly into them. Once this is done, footings and blocks are laid to support the home’s weight. The crawl space walls can be made of concrete blocks or poured concrete. A properly constructed and well-maintained crawl space has a service life of at least 50 years.
Types of Crawl Space Foundations
A crawl space can be vented or unvented. Let’s look at both briefly.
Vented crawl space: This type has operable air vents on all its walls. These vents are usually installed on the upper section of the foundation wall. The FHA recommends a minimum of one square foot of vent for every 500 square feet of space.
Unvented crawl space: The second type has no vents. For it to work, it must be integrated with the conditioned space in the house. The advantage of this is that all ducts and pipes running through the crawl space are more protected.
Advantages of a Crawl Space Foundation
Accessible utilities: A crawl space makes it easier to access all your home’s piping, wiring, and ductwork during inspections or repairs.
Warmer floors: The floor of a conditioned crawl space won’t feel like it’s made of concrete as it will be warm.
Valuable storage space: When a crawl space is insulated, it creates ample storage for various items that is not susceptible to moisture.
Flexibility: In areas with expansive soils, a crawl space foundation responds better to hydrostatic pressure than slab-on-grade foundations.
Disadvantages of a Crawl Space
On the flip side, most crawl spaces are prone to moisture issues, which can lead to mold or fungi growth. They are also vulnerable to storms and offer almost no protection from inclement weather. That’s not to mention that moisture control and temperature control can be elusive.
Protecting the Crawl Space
There are many things you can do to create a dry, warm crawl space that is inhospitable to mold and pests. One of the most important is crawl space encapsulation. This entails covering the walls and floor of your crawl space with a 20-mil plastic barrier. Encapsulation prevents condensation, mold growth, stuffiness, and wood rot among other issues. But before doing this, cracks have to be filled and vents sealed. Otherwise, you will have problems controlling moisture.
It’s also crucial for the crawl space to be insulated with foam board and spray foam. These materials help retain the crawl space heat. When the temperatures change, you won’t feel the fluctuations.
Should You Build a Crawl Space Foundation?
A crawl space foundation works best in scenarios where a concrete slab foundation isn’t an option. If you experience any of these three situations, it’s best to go with a crawl space.
Uneven ground: When building on land that’s not level, a contactor can alter the height of blocks and piers in the crawl space to level off your house.
Flooding: While crawl spaces are prone to moisture, they are certainly much better in areas where flooding is a problem. The 18 inches of clearance allows water to pass without pushing your home.
Earthquakes: Unlike slab foundations which crack, crawl space foundations can withstand lateral movements and undulations from an earthquake.
If you would like to encapsulate your crawl space to keep moisture out, contact Foundation Recovery Systems to schedule a free crawl space inspection. We’ll enclose the crawl space with a heavy-duty vapor barrier so moisture won’t trouble you again.