You may be wondering why home builders leave that space under the house and what purpose it holds. Well, there are multiple reasons actually and we will cover them all. Additionally, we'll discuss the advantages and disadvantages of a crawl space compared to a basement or slab foundation.
There are many reasons why a crawl space is such a popular form of foundation for homes and of course one of the most considerable reasons is price. And while building over a basement can be much more costly than a crawl space, building on a slab can in fact be a cheaper option. So why not build on a slab instead of a crawl space? Well for one, a slab is poured on top of the soil and when the soil settles or shifts you are in danger of cracking the foundation. So even though it is initially less expensive to build on a slab, foundation issues on this type of house can be extremely costly. Crawl spaces, on the other hand, have footings deep down under the house. These footings protect the foundation from most soil settling, as long as drainage for the home is taken care of appropriately.
Another factor in determining which type of foundation to use is accessibility to utilities such as electric, HVAC, and plumbing. Slab offers little accessibility to utilities since the house sits directly on the foundation. While a basement offers a little better accessibility, it can still be a hassle and very costly if something goes wrong in hard to reach areas. This is where the crawl space flourishes by offering unrestricted access to all utilities under the house for inexpensive services.
Crawl spaces most commonly have a dirt floor but can sometimes have sand or rock throughout. Sand or rock may let any water that enters the crawl space travel through quicker but your service providers will not be a fan and may charge more if they have to crawl around on rocks digging into their back or knees. Dirt floors work just fine as long as precautions are taken to keep water out from under the house and a good moisture barrier is installed throughout the crawl space.
The disadvantage to having a crawl space foundation is that it adds another area for the homeowner to look after. Only problem is most homeowners want nothing to do with the crawl space. I mean who wants to go crawling around under the house with spiders and who knows what else? So a high percentage of crawl spaces are being neglected which can lead to costly repairs when a problem does come to light.
Certain foundation types can be more common depending on your area and the builder. Here in Western Kentucky, crawl spaces are by far the most popular form of foundation. If you have a crawl space, be sure to get in there or have a local professional check it out at least once a year to make sure your home's foundation is healthy.