8 Types of Footings Used in Building Construction

If you are planning to build a house or any other structure, you might have heard of the term "footing" in construction. But what is a footing and why is it important? 

Footings are the most important part of foundation construction. They are the base of a structure that spreads the building weight evenly across the soil, preventing it from sinking or collapsing. Footings are also important for preventing water and moisture from seeping into the foundation, which can cause cracks and other damage. Naturally, depending upon different soil settings and house loads, there are different types of footings one can choose from.

Let us learn more about the topic so that you can choose the right type of footing for your project.

Importance of a Footing in Construction

Here are some of the key importance of footings in construction:

• Distributes the weight of the building evenly. Footings spread the weight of the building over a larger area of soil, which helps to prevent the soil from becoming overloaded and sinking.
• Prevents excessive settlement. Excessive settlement can cause cracks in the foundation and walls, as well as other structural problems. Footings help to prevent excessive settlement by spreading the building weight evenly and by ensuring that the footings are deep enough to reach stable soil.
• Minimises differential settlement. Differential settlement occurs when different parts of a foundation settle at different rates. This can cause cracks in the foundation and walls, as well as other structural problems. Footings help to minimise differential settlement by ensuring that the footings are all the same depth and spread out the building weight uniformly.
• Prevents sliding and overturning. Footings help to prevent the building from sliding or overturning by providing a large surface area for the building to rest on. In short, footings are critical for the structural integrity of a building. They help to prevent the building from sinking, collapsing, or sliding, and they also help to protect the foundation from water and moisture damage.

Types of Footings Used in Building Construction

There are many types of footings used in building construction. They are selected on the basis of the type and condition of soil, the depth of the safe-bearing strata, and the type of superstructure. Some of them are:

1. Isolated footings: They are the most common type of footing. They support individual columns or posts. Isolated footings are usually square or rectangular in shape, and they are made of concrete.
2. Combined footings: They are used to support two or more columns that are close together. Combined footings are typically trapezoidal in shape, and they are made of concrete.
3. Strip footings: They are used to support long foundation walls. Strip footings are mostly rectangular in shape, and they are made of concrete.
4. Raft footings: They are a type of mat foundation that is used to sustain an entire building’s weight as evenly as possible over a grand area. Raft footings are made of concrete.
5. Pile footings: They are used to support buildings, typically when they are built on top of poor, less enduring soil. Pile footings consist of tall, thin columns that are pushed into the ground.

Ultimately, the type of footing that is used will depend on the building weight, the type of soil, and the depth of the frost line. Here are some additional types of footings that are less common:

1. Strapped footings: They are used to prevent isolated footings from spreading apart. Strapped footings are typically made of concrete, and they are attached to the isolated footings with steel straps.
2. Sloped footings: They are deployed in regions with sloping ground. Sloped footings are typically trapezoidal in shape, and they are made of concrete. The slope of the footing helps to distribute the structure's weight evenly over the sloping ground.
3. Stepped footings: They are installed in places with deep frost lines. Stepped footings are typically made of concrete, and they have a series of steps that gradually increase in depth. The steps help to distribute the building weight evenly over the deep frost line.

Conclusion

As you have learned, footings are essential components of building construction that provide robust structural support and steadiness. There are different types of footings used in building construction depending on various factors such as soil conditions, load requirements, and structural design. 

Ultimately, choosing the right type of footing for your project requires careful planning, analysis, and engineering. You should also follow proper construction practices and maintenance procedures to avoid common problems with footings, such as settlement, frost heave, and corrosion.