What are the basics of concrete footings? Concrete footings function to safely transfer all structural loads from the foundation (the earth) to the building (dead load, earth load, and live load). Of course, the foundation on a house is also vital from a structural viewpoint. But when it comes to load capacity, the foundation may be king... at least in terms of load capacity on the average residence!
For a typical home, the foundation can consist of either an internal concrete slab exterior concrete slab, or wood footing with a built-in concrete slab. And depending on the climate and soil conditions in your area, there are additional components that can be added to the basic foundation such as metal flashings, metal tiebacks, and/or stone trim. When you're shopping for your building pad, you will find that there are many options to select from, including various concrete footings sizes, precast or poured designs, stamped or factory finished surfaces, poured designs with metal ties or rebar in them, and of course, pre poured designs with fear in them. With so many options available, it can be difficult to pick a footing size that is right for your home. But here are some of the main options and their purposes:
Spread Footing - This type of construction uses pre-cast or poured concrete footings that are constructed at the location where the new home is to be built. The primary purpose of spread footing is to create a waterproof surface for walking and parking areas around the structure. Typically, this type of construction includes concrete slabs that are set into the ground in thin strips, which are then expanded horizontally to cover the entire area. This construction method is not without flaws, as these slabs can become weak and brittle over time, especially when cold weather sets in. By using steel ties or refer to anchor the concrete footings to the surrounding soil, however, this problem is often avoided.
Concrete Trench System - Also known as a "tub" or "dressing system," trench footings are a unique form of laying concrete around an existing foundation wall. Essentially, the concrete is poured directly onto the soil beneath the foundation wall, and spread to the depth needed to completely cover the wall. Unlike spread footing, the concrete that is used in this method must be cut with precise lengths to fit tightly around the corners of the foundation wall. When doing so, it is necessary to set the concrete in place using steel ties or rebar, and the length of each of these pieces must be precise. If done incorrectly, these footings can weaken the walls of your home. Learn more about EXCAVATING services on this page.
In addition to these two major types of footings, there are also sub-base footings that can be used on structures that have a higher degree of structural stability. These sub-base footings are placed on structures that are in need of stabilization, but which do not have the height or width of the foundation wall. These footings are typically used for structures that are less than fifty feet in height, and for structures that have a low degree of vertical stability. These footings are placed on soils that are lower in water content, and they generally come in different thicknesses depending upon the type of soil that is in use. Generally, these soils have a medium to low water retention ability.
Regardless of the type of footings you choose to install, make sure that they are installed properly. They should be constructed and installed by a professional engineer and architect. Although this may seem like an expensive task, it can actually save you a lot of money in the long run. Often times, footings may need to be replaced due to excessive wear, because they were not built properly. You may also want to contact a local soil engineer to discuss your soil conditions and to discuss ways to better sustain your foundation's health.
Check out this related post to get more enlightened on the topic: https://www.encyclopedia.com/science-and-technology/technology/technology-terms-and-concepts/concrete.