Curious about crawl space foundations? Great! RegionalFoundationRepair is at your service 24/7. In this guide, we cover common questions like:
- What Are The Different Types of Crawl Space Foundations?
- What Are The Benefits and Advantages of Crawl Space Foundations?
- What Are The Common Problems of Crawl Space Foundations?
- What Are The Correct Conditions for a Crawl Space Foundation?
Want a quick pricing quote on crawl space foundation repair or installation? Tell us about your project in the form, and we’ll get you connected with one of our foundation repair technicians in your city, or continue reading to learn about crawl space foundations.
What Is A Crawl Space Foundation?
A crawl space foundation is a home foundation that is built partially below ground and offers an under-home area for storage or access to utilities. Unlike a full basement, crawl spaces typically provide just three to four feet of vertical space between your first floor and the soil below.
Our first order of business when installing a crawl space foundation is ground preparation. This process involves leveling the soil, removing organic material, and excavating to the depth of the crawl space.
Some homeowners request that we install a concrete slab to act as the floor for their under-home area. If that is the case, we’ll follow soil preparation by laying down and leveling sand to improve drainage beneath the slab once it has dried.
Next, we’ll pour the footings for the foundation walls, followed by the slab if the homeowner prefers not to have a dirt floor. Once the slab is dry, we build the molds for the poured concrete walls on top and begin pouring, or we move onto construction of concrete block walls, again depending on the homeowner’s preference.
At Regional Foundation Repair, we believe that every foundation should be responsibly constructed with longevity and safety in mind. That’s why we generally install footing drains or French drains, apply vapor barriers, and use other waterproofing equipment and materials on the crawl space walls while they are exposed.
Finally, we backfill around the walls and compact the soil to prevent excessive settling and intense hydrostatic pressure on the concrete walls down the road.
There are several benefits to constructing crawl spaces as opposed to other types of foundations. The first and often the most important for many homeowners is affordability. Full basements are desirable because they add living space to your home, but the excavation to eight feet is very time-consuming and expensive. Crawl spaces still offer storage and access to utilities, and we can charge significantly less because they aren’t as time-consuming to construct.
Another benefit when installing a crawl space foundation instead of a full basement is the timing of the project. Full basements take significantly longer to build and dry, especially if the homeowner prefers a cinder block wall rather than poured concrete walls. Crawl Spaces take longer to install than a slab, but they can often cut the construction time of a basement significantly.
There are some drawbacks we encounter when installing crawl space foundations. The first issue is that they require extensive land preparation. No matter how well we construct and prepare crawl space walls for a new home, the space will be prone to moisture problems. Humid air and water are naturally attracted to underground areas, so we must take great care to grade the land properly, ensure a drainage system is in place, and waterproof the concrete.
Weather can potentially be a drawback when we build a crawl space, as the concrete needs to remain dry while it cures. Rain and snow can cause construction delays and extend the total project time unexpectedly.
What Are The Correct Conditions for Crawl Space Foundations?
Crawl spaces are ideal in areas where the frost line is too deep for slabs but not quite deep enough to necessitate a full basement. The frost depth refers to how far below ground level the earth freezes in the winter, and plumbing lines and concrete footers must be placed below this depth. Moderately cold climates may require a crawl space, and this foundation design will allow for appropriate routing of utilities.
Crawl space foundations are also best in relatively dry areas, as the space beneath your house will be prone to moisture accumulation. A property that receives below-average or average rainfall and isn’t close to coasts where the groundwater is very shallow will generally be best for crawl spaces.
What Are The Types of Crawl Space Foundations?
There is really just one style of traditional crawl space foundation, where your home sits at or slightly above ground level with a void several feet below the earth’s surface. However, there is one variation that is similar in construction, which we’ll explain below.
Below-Grade Crawl Space Foundation
As most people define it, a crawl space foundation is an under-home area situated beneath the ground level. Your structure sits at or slightly above the earth’s surface, and the crawl space walls are mostly set into the ground and covered by soil.
This traditional crawl space foundation provides storage space or access for utility repairs and home inspections without raising your house to a significant level above the ground.
Below-grade crawl spaces always include a concrete wall around the perimeter of your home. However, the floor can either be dirt or a concrete slab poured before the walls are constructed.
What Are The Benefits and Advantages of Crawl Space Foundations?
Crawl Spaces provide a number of benefits to homeowners, which we’ll discuss in-depth below.
Provides Storage Space
One of the most compelling reasons homeowners opt for a crawl space foundation is the added storage space. When our specialists construct crawl space foundations, we ensure that the risk of moisture accumulation is as minimal as possible. This makes the area suitable for storage that you wouldn’t get with a concrete slab foundation.
Home mechanicals can often be placed in your crawl space rather than in your living space or outside your home. Some homeowners find the area suitable for oil tanks, HVAC equipment, dehumidifiers, and even your boiler and hot water heater if local building codes allow for it. This frees up quite a lot of space in your living area, increasing the value of your home and the space you have indoors.
Suitable for Sloped Lots
Unlike slab foundations, we can safely and affordably install crawl spaces on sloped lots. In areas with frequent or rapid changes in elevation, slabs may not be possible. If they are, excessive excavation to level the ground and installation of a large retaining wall may be required before construction can begin on the foundation. Crawl Spaces make the process much less time-consuming and more affordable.
Suitable Atop Expansive Soil
A major downside of slab foundations is that they are very prone to differential settling and upward soil expansion, often suffering a loss of structural integrity. Crawl Spaces are set on footers that reach down to a safe level of the soil and don’t depend on the soil near the earth’s surface for support. The result is less of an effect when the ground below your home shifts with changes in moisture.
Suitable in Flood Prone Areas
We can safely build crawl space foundations in flood zones without worrying about flood water entering your living area in most cases. Above-grade crawl spaces are better for allowing water to flow freely beneath your home, but even below-grade crawl spaces can allow water into them without allowing it to affect your wooden construction materials beneath your first floor.
Easy Access to Utilities and Underside of Home
Lastly, crawl spaces are perfect for running utility lines like plumbing pipes, electrical wiring, and HVAC ductwork without going up through your attic or behind your walls. Any repairs to these lines will be much more straightforward, not to mention more affordable, as no excavation through a concrete slab will be required.
Additionally, home inspectors and termite inspectors can easily access the underside of your house for their examinations. This generally doesn’t decrease the price of the inspections, but they will be more thorough.
What Are The Common Problems of Crawl Space Foundations?
Crawl spaces are convenient and beneficial for many reasons, but they are far from perfect. Below, we’ll include the biggest drawbacks of this foundation style.
Prone to Moisture Accumulation
The biggest complaint homeowners have about crawl space foundations is that they are prone to moisture build-up. Humid air from outside will work its way in over time and get trapped in the space under your house. As moisture accumulates, the risk of mold growth and wood rot increases.
Some species of mold can eat away at the wood construction materials under your house, gradually deteriorating floor joists or support beams. Structural damage can occur if the mold and moisture go untreated. Additionally, mold can become airborne and pollute your indoor air, causing allergy symptoms and respiratory distress in some homeowners.
Even if mold and mildew aren’t a problem, moist air beneath your house can seep upstairs, making your air temperatures feel more extreme and increasing your utility bills.
Prone to Pest Infestation
The moisture that naturally builds in crawl spaces also attracts pests to the under-home area, which isn’t an issue for slab foundations. Rodents and insects can be a nuisance, but more importantly, they can cause damage to your house. Rodents can chew through utility lines, and wood-destroying insects like termites and carpenter ants can eat away at your building materials, leaving you with costly structural damage over time.
Not Energy Efficient
At Regional Foundation Repair, we go to great lengths to insulate and seal your crawl space to restrict airflow from the outside. However, no foundation is impervious to outdoor conditions. Cold air and moisture will inevitably enter the space and accumulate.
The air from beneath your house naturally enters your living space through a process called the stack effect, so you’re bound to lose heat to your crawl space and have increased humidity on your upper floors.
The result is a less energy-efficient home than you’d enjoy with a slab foundation. You’re likely to experience slightly less comfortable indoor air temperatures as a result, as well as higher utility bills.
Traditional crawl spaces require fairly extensive excavation, as about four feet of soil needs to be dug out across the entire footprint of your house. The process is much less time- and labor-intensive than the excavation for a basement foundation, but it will inevitably be longer than the preparation for a slab or pier and beam foundation. Ultimately, your cost will be higher than some more straightforward foundation installations.
Crawl space foundations are popular construction choices for many homeowners because they provide an under-home space for storage and easy access to utilities while remaining cheaper than full basements. They do come with their issues as well, including an increased likelihood of moisture issues, water damage, mold growth, and pest infestation, all of which can damage your structure and decrease your indoor air quality.
At Regional Foundation Repair, our foundation experts specialize in building, maintaining, and repairing crawl space foundations. If you’re looking to have a crawl space built or need repairs or waterproofing for your existing crawl space, simply fill out our contact form, and we’ll get you in touch with one of our highly-trained professionals right away!