What Type of Foundations are Used for Commercial Buildings?

What Types of Foundations are Used for Commercial Buildings?

Piles

There are two types of commercial foundations: deep and shallow foundations. A pile foundation is a deep foundation because it reaches deep into the ground, through unstable soil, to rest on the rock below. Piles look like long cylinders or columns made out of concrete or steel. These piles are designed to transfer the load of the building at the desired depth by end-bearing. Piles are ideal for situations where there is a change of high water content in the soil, such as a high groundwater table or a nearby drainage system. Piles also work in cases where live loads may be heavier or not as uniformly distributed.

T-Shaped Foundations

A t-shaped foundation is ideal in environments where the ground frequently experiences freezes. The concrete footings rest just below the frost line and then walls are built on top of those footings to extend past the surface of the soil. Taller structures in areas where the ground is more likely to freeze use t-shaped foundations because the foundation helps to evenly distribute pressure from frozen soil.

Spot Footing

Spot footing, or continuous footing, is a type of shallow foundation that is commonly used for commercial foundations. The footing carries columns or grade beams to distribute the structural load into the soil around the building’s foundation. Spot footing supports a single point of contact, like a beam or post. Materials like concrete and rebar are often used to reinforce the foundation and help it carry more weight.

Spread Footing (Individual Footing)

Spread footing is designed to support foundations where the base of the foundation is wider than the top. Spread footing is built with concrete and rebar and performs better than other spot footings because they “spread” the weight of the foundation out over a large surface area.

Mat Foundation

Mat foundations are another type of shallow foundation. This foundation is also called a raft foundation and is most commonly used when the soil beneath the foundation has a low load-bearing capacity. The mat foundation spreads out the building’s weight – dead and live loads – and evenly distributes the weight of the structure across a greater surface area. This foundation is engineered to float the entire building at ground level as the whole foundation works similarly to a concrete slab foundation.

Slab Foundation with Grade Beams

A slab foundation, or a slab-on-grade foundation, is a choice often used for commercial buildings because it’s an economical choice. Grade beams, reinforcements, and castings are all pored together with the concrete slab to support the building’s walls with a uniformed load. This foundation type is seen more often in areas where the ground is less likely to freeze.