A concrete foundation forms the base of a building or structure. Most homes today use poured concrete for the foundation, and with good reason. As a construction material, concrete is very durable. In terms of design, using concrete also allows greater flexibility for building and homeowners.

Structures that have a concrete foundation are more resistant to rot and decay, have longer life spans, and are safer when it comes to fire and water damage. Concrete requires virtually no maintenance and you never have to worry about humidity or temperature changes.

Types of Concrete Foundation

Depending on the purpose of the slab, you have three choices when constructing your concrete foundation. Each one has its own distinct pros and cons. Here are a few of the concrete foundation types that are typically used in modern construction:

Slab-on-grade

A slab refers to one concrete layer that varies in thickness. It is monolithic or poured all at once. The edges are generally thicker to ensure proper drainage. A slab on grade foundation design is typically used in areas where the ground does not freeze, however adding insulation can help improve its performance against frost heaves.

T-shaped

This is the most common foundation type for residential buildings. It is also usually used in places where the ground freezes during the winter since it is specifically designed to resist extreme weather changes. This type gets its name from the shape of the footing, which resembles an upside down T.

Frost-protected

This type is only seen with heated structures. It uses 2 sheets of strong, polystyrene insulation, which prevents heat loss and promotes heat retention. One of the sheets is placed outside the wall of the structure and the second is positioned at the base.

How to Build a Concrete Foundation

No matter what type of concrete foundation you want for your home, you’ll need to follow the same steps for construction. Ensure that the pouring is done properly to avoid compromising the structure and integrity of the entire building.

If you are wondering about how to build a concrete foundation for a house, here is a basic guide to help you out:

1. Measure the size of the slab and figure out how deep you need to dig to ensure that it fits.
2. Dig and excavate the area where the slab will be position. As a rule of thumb, dig down twice the thickness of the slab. This means that if the slab is 4 inches thick, the hold should be at least 8 inches deep.
3. Remove any debris from the hole and compress the soil with a compactor.
4. To protect the concrete flooring and prevent moisture from seeping, lay down a barrier.
5. Build a wooden frame to retain the concrete.
6. Pour the concrete into the wooden frame and wait for it to set properly. Ideally, you should wait at least 2 months before you install a hardwood floor.

Depending on the type of foundation, expect to spend between $4-7 per square foot for the concrete foundation cost. Shallow designs, which are set about 3 feet into the soil, cost less than deep foundations, which can penetrate the bedrock and are typically used for more difficult soil conditions.

Poured Concrete Foundation vs. Concrete Cinder Block Foundation

Poured concrete foundation uses wet concrete, trucked in and poured on site. Cinder block foundation, on the other hand, starts with concrete blocks that are then filled with concrete gravel.

Poured concrete foundation is the ideal option if you are looking for lateral strength, water resistance, versatility in forming shapes, flexibility with last-minute changes, and time and labor savings. On the other hand, concrete cinder block foundation is the better choice if it’s logistically impossible or more costly to truck in wet concrete. If weather conditions also prevent proper curing, a cinder block foundation might be worth looking into.

Concrete Foundation Design

In terms of design, concrete also offers more flexibility. Since it starts out as a liquid, poured concrete is capable of taking on any shape. The foundation design that you choose will largely depend on the type of soil that you’ll encounter on your construction site.

For instance, if you are dealing with chalk, you’ll need a deep foundation that is below any frost action. If the chalk is too soft for safe construction, you’ll have to dig deep until you reach firmer, more solid chalk. Our company will help you figure out which type of foundation is ideal for the structure you are building and the soil conditions present at your building site.

No matter what type of foundation design you are planning to do, you’ll need to adjust your plans to account for the soil conditions that you discover during the excavation process. Pay attention to any concrete foundation detail, including measurements, materials, and changes in your initial plans, since any mistake can get very expensive to fix later on.