A concrete foundation is the most common type of support for a home or commercial building. They’re a strong and cost-effective alternative to footings, piers or basements, and can help prevent damage from water, radon gas, and other hazards.
There are several types of concrete foundations, each designed to meet specific conditions and requirements. The most important thing to remember is that the right foundation is vital for the safety and longevity of your home or business.
Shallow foundations:
Typical residential construction uses shallow foundations, which are shallow trenches filled with gravel or rubble and then covered in concrete to provide stability. They’re a good option when the soil around the building is soft or shifting.
Poured concrete:
A poured concrete foundation is one of the most popular forms of concrete foundations because they are inexpensive and easy to build. They also require less maintenance and can be completed in a day or two.
They are more durable than concrete block foundations and can handle heavy vertical loads. They may be reinforced with rebar, which can improve their lateral strength and help prevent bowing from groundwater or shifting in the soil (lateral pressure).
The downside of a poured concrete foundation is that they can be more difficult to build than block walls because they need to be shaped before they’re poured. They’re also more susceptible to cracking and air pockets, which can weaken the concrete and compromise its integrity.
Insulated concrete foundations:
Insulated concrete foundations, or ICFs, are another popular form of concrete foundation. They are similar to slab-on-grade foundations but feature sheets of rigid, polystyrene insulation laid flat on top of the gravel base and on the outside of the wall before cascading the concrete slab. The insulation helps to retain heat and keeps the ground temperature above freezing near the footings.
ICFs are energy-efficient and a good choice for many climates, although they’re not without their own environmental issues. They aren’t recommended in areas with severe frost problems, since the insulation will lose heat to the ground when the ground is frozen.
T-shaped concrete:
This is the traditional form of concrete foundation and is often preferred for frost-prone areas, since it helps to avoid damage from frosty ground. However, T-shaped concrete walls can be prone to cracking when the concrete is resolved to a frigid temperature.
The disadvantage of a T-shaped concrete foundation is that it can be more expensive to build than a slab-on-grade or a frost-protected concrete foundation. This is largely due to the costs involved in having the polystyrene insulation laid down.
They’re also more prone to leaks than other types of concrete foundations, so sealants should be used to protect the structure from moisture.
Other foundation types include masonry, which is a popular option for small homes and commercial buildings. Masonry foundations are also more affordable and can be built quickly.