A footing is a foundation beneath a building. Its purpose is to prevent the structure from sinking into the ground. If the foundation is too shallow, it can cause the system to sag and collapse. Moreover, if the footing is too thick, it can cause it to collapse. An adequately designed foundation should prevent this from happening. For this reason, bases made of concrete are recommended.
Footings are typically large concrete masses with rebar embedded in it. Their primary function is to support an entire load of whatever is built above. Residential homes usually rest on a footing. They are used for many smaller as well as large construction projects. They are the anchors that keep the structure in place. If you want to avoid foundation failure, concrete footings are the solution. Here’s how they work:
The essential ingredient in concrete is water. This ingredient helps the concrete retain its compressive strength and is a crucial element in the foundation’s integrity. Depending on the weight of the footing, concrete mixtures will vary in strength. You can read about the required mix on your blueprints. Make sure you have the proper water, cement, and rebar ratio. Unless you plan to put the footing under a large load, choose a minimum of 3500 psi concrete.
A concrete footing’s density depends on the soil’s moisture content. Dry soil will drain the concrete mix and weaken the foundation. To prevent such a situation, you must dampen the soil before pouring the concrete. You can also use a pump to pour the concrete directly into the footing. The placement of the ground depends on the circumstances of the construction project.
The footings are usually reinforced with rebar. It reduces the possibility of concrete cracking and can resist moisture penetration and lateral forces. In addition to this, rebar minimizes the risk of the structure shifting in the future. Hence, rebar is a must for footings. So, when you are building a home, make sure to choose the best foundations for your home.
In general, footings are designed to resist upward-acting soil pressure. The pressure exerted on foundations tends to bend the structures upward. In the case of reinforced concrete foundations, the ACI-318 standard describes three failure modes. Bearing is one of these failure modes, although this failure mode rarely applies to residential loading conditions. This failure mode is rarely an issue, so the designer should consult this document for guidance.
A concrete footing’s thickness is determined by the weight of the structure on it. Generally, foundations can support up to 49 inches of weight. Typically, the soil must have a bearing capacity between 1500 and 12,000 psf. Its depth should be a minimum of 2 inches from either face of the foundation wall. This allows for a certain degree of construction tolerance. If the foundation is too shallow, it may not be able to support the weight.