A strip foundation is a type of foundation that is often used for low to medium rise residential buildings. This type of foundation is generally inexpensive to build, and allows for simple formwork structures. However, strip foundations do have disadvantages. These include the potential for structural integrity problems and bending failure. They also have low durability. Therefore, they are not ideal for high rise construction projects.
One of the major advantages of strip foundations is that they can be constructed in a relatively short amount of time. Nevertheless, they should not be used for monolithic binding of floor and basement. For that, a more durable and economical option would be reinforced concrete. In addition, the thickness of a strip foundation should not be less than 150mm.
The width of a strip foundation depends on a number of factors, including the size and condition of the subsoil, the load-bearing capacity of the soil, and the building’s height. The traditional width of a strip foundation is three times the wall’s overall width. On sloping sites, however, a stepped foundation may be necessary.
Most strip footings are usually twice the width of the wall. Often, a strip footing will also be reinforced, depending on the soil’s bearing capacity. In some situations, reinforcement is needed to prevent shear or bending failure. Depending on the site and load-bearing requirements, a strip foundation can be built to meet local building regulations.
Strip foundations are designed to withstand longitudinal forces from thermal contraction and thermal expansion. When designing a strip foundation, a 45 degree angle is considered, as this will ensure that the load is evenly distributed across the foundation. While this design can be effective for small to medium-sized buildings, it is not advisable for buildings taller than four stories.
The width of a strip footing will vary from 70 to 90 cm. It is normally two to three times the width of the wall. During construction, the strip footing can be stepped, but this is a costly and time-consuming procedure.
If the strip foundation fails, the underlying foundations can collapse. A strip foundation is not a good choice for a structure that has high localized loads, such as columns, and should therefore be designed to accommodate these.
There are other types of foundations, such as pile foundations, which are used in situations where the bearing capacity of the soil is insufficient. Although they are not as simple to construct as a strip foundation, they offer many benefits. They are especially useful for light structural loads, are a cost-effective way to build, and can be used in most subsoils.
As with any type of foundation, there are limitations to its use. They are best suited for residential buildings and low-rise, non-commercial buildings. They are not a good solution for commercial buildings, which are subject to heavier loads.
Whether a building is designed for a commercial or residential use, it is important to determine its overall height. For a low-rise building, a 600mm wide by 250mm deep concrete strip foundation is the most common choice. For a high-rise building, a deeper foundation is required.
