Purpose. Foundations offer the structure's ground stability: they disperse the structure's weight across a vast area to avoid overwhelming the underlying soil (possibly causing unequal settlement). They also provide a stable base for wall and floor construction.
There are two types of foundations: deep and shallow. Deep foundations are constructed well below the frost line to take advantage of the ground's constant temperature. These include poured concrete, brick, stone, and metal frames. Shallow foundations are built up above the frost line using dirt or sand as far as practicable. These include block walls and flat roofs. In areas that experience heavy snowfall, hollow blocks with steel reinforcing bars inside can be used instead. Hollow blocks are not recommended for areas where there is a risk of flooding.
The type of foundation you choose depends on several factors such as climate, site conditions, and architectural style. Where possible, it's best to use deep foundations because they're more efficient at dispersing the load over a large area and thus require fewer supports. However, if this isn't possible then shallow foundations will do in a pinch.
It's important to remember that even though a foundation may appear to serve its purpose, it still needs to be maintained regularly in order to remain effective.
The primary roles of foundations are as follows:
The primary function of foundations is to allow the structure's weight to descend into the earth without sinking! When a structure is built on the ground, it exerts a force on the earth. That load is carried by safe foundations, so the earth is not overburdened. Buildings with bad foundations may sink into the ground or collapse under their own weight.
The four main functions of foundations are protection, support, transmission, and connection. Protection involves preventing damage from water and other elements; this is most important in coastal areas and in high-risk buildings such as hospitals. Support means providing stability for other parts of the building, such as walls and roofs. Transmission allows the transfer of loads between components of the building, such as floors and ceilings. Connection refers to the way foundations connect a building to its surrounding environment. For example, they may provide access for air conditioning equipment or sewer lines.
Protection: The first line of defense against damage from the outside world is the foundation. It should prevent water from entering the building and should be able to withstand heavy rainstorms and seismic activity. A low-cost option is a simple layer of sand placed beneath the floor slab. This provides some insulation from heat and cold and reduces noise when footsteps cross sand. A more extensive system might include an underground room filled with polystyrene beads. This is called a bead wall and is used because it gives better sound isolation than dirt does.
Foundations are essential to securely transfer the load of the building to the ground. As a result, all structures need have suitable foundations (often concrete), which will vary from project to project based on the specifics of each situation. The Building Regulations require that you consider several factors when choosing a foundation for your home, including soil type, drainage, existing structures, and so on.
The Building Regulations also specify how deep foundations must be. They can be between 0.6m and 1.5m deep, depending on the risk of flooding in your area. If flooding is unlikely, shallow foundations up to 0.3m deep can be used instead. Shallow foundations are easier to construct but they cannot carry as much weight as deeper ones.
The depth of your foundation should be sufficient to prevent water reaching the base of the house under normal conditions. This means that if it rains heavily or if there's a risk of floodwater appearing on your property, you'll need to build a deeper foundation. Of course, if the soil at your site is very wet or marshy, it may be necessary to go deeper than recommended by the Building Regulations.
Professional advice should be sought by anyone considering whether to use shallow or deep foundations.