With a slab foundation, the property is constructed on top of a thick, level concrete slab. For a crawl space, exterior concrete walls raise the foundation a minimum of 18 inches above ground level, which leaves access space for wires, plumbing and storage.
Concrete Slab Foundations
Concrete slab or slab-on-grade foundations are solid concrete foundations that rest on the ground and usually have mesh or rebar reinforcement. They are usually 4-6 inches thick and are more effective on level ground or minimal slope.
Wood foundations can be identified, like concrete slab foundations, by looking at a home's exterior and searching for wood between the exterior walls and the ground. Stone foundations are characterized by the presence of stones at the base of the exterior walls of the house.
Three common house foundation types include basements (30 percent), crawlspaces (15 percent), and concrete slabs (54 percent).
The house is then constructed on top of this concrete foundation. Slab foundations are more common in southern states with warm climates, where the ground is less likely to freeze and cause the foundation to crack. Here's a look at the pros and cons that come with a slab foundation.
Slab homes are more likely to experience severe foundation cracks than other foundation types. Damage may come from shifting soil, tree roots, freezing temperatures, or natural disasters. These cracks compromise the home's structural integrity and can lead to other issues, such as water infiltration and mold growth.
A foundation can maintain its integrity through timely repairs, soil compaction, and protection. For the average home, foundation should last about 80-100 years before needing to be replaced. But not repairing your foundation will make that number of years a lot smaller for your home.
The easiest way to determine your foundation type is to look at the exterior of your home. If your house sits directly on the ground with no visible crawlspace, it likely has a concrete slab foundation.
Poured concrete is the strongest type of foundation for a house. Concrete is incredibly strong and durable, and it can be poured into any shape. This makes it ideal for supporting the weight of a house. Block foundations are also very strong, but they are not as flexible as poured concrete.
A footing is the base that sits on the earth/ rock and usually supports the loads above and on it. A slab is between footings, sometimes sits on footings or part of footings. Sometimes slabs are between walls or outside walls. The do not always take load but can be designed that way.
Typically a house built on a slab will be lower. look below the siding at the foundation. A crawl space is required to be a minimum of 18 inches. If you do not see at least 18″ of concrete or cement, it is likely slab on grade construction.
Take a good look at the veins on your wrist under natural light for an easy way to determine your undertone. If your veins look green, it is likely you have warm undertones; if they are blue/purple, you have cool undertones. If they appear blue/green or match your skin colour, you most likely have neutral undertones.
Slab foundations are considered a better option in warmer climates where the depth of the frost line isn't an issue because they're more affordable, but crawl spaces are better in areas where the frost line is deep or where flooding can be an issue.
You may have heard the terms slab foundation and slab on grade foundation being used interchangeably, and that's because they are the same thing. This type of foundation is commonly used in warmer climates where the ground doesn't freeze and doesn't require excavation, like in the case of a basement.
Water Damage
A cracked foundation is like an open invitation for water and moisture to seep in. Especially if you have a basement or a lower level more susceptible to the elements, you may begin to notice water damage emerge.
With a slab foundation, the property is constructed on top of a thick, level concrete slab. For a crawl space, exterior concrete walls raise the foundation a minimum of 18 inches above ground level, which leaves access space for wires, plumbing and storage.
The three most common foundation types are: basement, crawlspace, or slab-on-grade. While other variations are possible, these are the main options you will encounter when you build your new home.
Increased Foundation Cost: A basement is understandably the most expensive foundation-type of the three mentioned here — more so if you choose to finish that space.
A slab-on-grade is a type of shallow foundation in which a concrete slab rests directly on the ground below it. A slab-on-grade foundation usually consists of a thin layer of concrete across the entire area of the foundation with thickened footings at the edges or below load bearing walls in the middle of the building.
Look for cracks in the foundation, walls, or floors of your home. Also, check for uneven floors or doors that do not close properly. Examine the exterior of your home for any signs of sinking or settling, as well as water damage and mold, which can all be indicators of potential foundation issues.
Slab leaks can be found either on the pressure side or the drainage side of your foundation. If the slab leak is on the pressure side of the water system, it can typically be unearthed prior to triggering a lot of destruction. While these leaks are usually found quickly, they can cause significant damage.
If your home is undergoing a renovation or remodel, you may want to consider repiping a house built on a slab during the construction project. It's easier to replace pipes inside walls before hanging drywall. Brass and copper pipes tend to last 80 to 100 years. Galvanized steel may only last 70 to 80 years.
While it's not always the first choice, a pier foundation is one of the sturdiest and longest-lasting solutions. It provides excellent support and doesn't come with some of the potential negatives that are associated with basements and crawl spaces.