Foundations are the first part of any construction. They are incredibly important to the durability of a building, and if not completed correctly, they can affect the strength and resilience of the building once completed. In short, without a stable foundation, a building will not be reliable nor last a long time.

With vast experience in structural engineering, Martin Perry Associates has created this article to explain what foundations are, their functions and the types of foundations and their uses.

What is a Foundation?

A foundation sits between the building and the ground, making it the lowest part of the structure.

It distributes loads from the house to the soil, and it is integral that it is strong enough to withstand the entire weight of the building.

What are the Functions of a Foundation?

A foundation serves many functions which we will explain below.

A house being constructed with scaffolding

Helps to Avoid Compounding Defects

One integral part of a strong foundation is that it maps out the rest of the building’s construction. For example, if a foundation provides an unlevel surface to build on, this will only be enhanced and worsen as the structure continues to be built upwards.

The inadequacy of a foundation creates a domino effect for other parts of its construction, and without it acting as a stable starting point, the base, support beams and walls will follow suit.

The decline of a building’s structure through the development of its construction from a poor foundation is professionally referred to as compounding defects. Essentially, it indicates that the building will fail because of the issues caused by an insufficient foundation which cannot be corrected through its construction.

Holds the Entire Structure

An obvious purpose of a foundation is that it supports the whole building. Therefore, it needs to be correctly formed with the highest quality and reliability as it needs to keep the rest of the house upright.

If you don’t invest appropriately at this stage, it could cause many costly repairs and modifications later on, which could have been avoided at the beginning of the process.

Prevents Overloading

As previously mentioned, a foundation distributes the weight of a building to the ground. Therefore, by transferring a building’s load far into the ground, it offers stability to the building and helps to avoid any overloading on other parts of the structure.

Types of Foundations

A foundation is commonly created with concrete because of its versatility. To construct the foundation, concrete is applied to a wooden frame which forms the ‘slab’ shape. The wooden frame is then removed once the concrete is set.

The type and mix of the concrete used will vary from project to project. Amongst other factors, the chosen concrete mix will rely on the strength required of the foundation as well as the available finance.

Not all foundations are exclusively concrete, and they can differ in their production. The type of foundation is dependent on the purpose of the building and where the building is situated.

In general, foundations are divided into two clear types, which can be further separated into additional categories. The two primary forms of foundations are shallow and deep foundations which are explained more below.

Two builders working on a construction site

Shallow Foundations

Shallow foundations are roughly one-to-three metres in depth. As expected, they don’t distribute loads far into the ground. For this reason, they tend to cost less than deep foundations as they require less labour and resources to implement.

Examples of popular shallow foundations include:

• Strip foundation- These foundations are commonly used for load-bearing walls.
• Trench foundation
• Raft or mat foundation
• Combined footing
• Individual/ isolated footing

Deep Foundations

As the name suggests, deep foundations are dug much further into the ground’s surface to reach the subsoil which lays beneath the weaker topsoil. They are often preferred if creating a high building or if the ground is weak.

Examples of deep foundations include:

• Pile foundations
• Drilled shafts or caissons

Hopefully, we have provided you with a basic overview of the importance of foundations and how they affect the construction of a building.

If you currently need a professional engineer to oversee your construction project in the South West, we have structural engineers in Cornwall and Plymouth with a wide range of knowledge and expertise to manage your construction project from the beginning to the end. Please do not hesitate to get in touch for any assistance you require.