What are strip footings?
Strip footings are a type of footing usually used for the foundation of load-bearing or support walls, or can support a slab. Its composition is as follows: A strip footing is a (relatively) small slab of reinforced concrete placed in a trench, this is usually reinforced with steel. This type of foundation is usually used for low to medium rise domestic buildings.
The width of the strip footing is determined by the bearing capacity of the soil. The greater the bearing capacity of the soil the lower the width of the strip footing needs to be.
How Deep Are Strip Footings?
The minimum depth requirement for strip footings will be dictated by the surrounding area’s soil conditions. However, as a general rule, the depth of strip foundations should be a minimum of 450mm below finished ground level to avoid frost damage if placed in frost susceptible ground.
The Pros and Cons of Strip Footings
The Advantages of Strip Footings
Strip footings have a number of advantages that make them one of the most commonly used foundations in domestic construction:
- Its construction is relatively cost effective as it is technically simple and usually does not require the use of heavy duty machinery.
- The walls of strip foundations are multi-functional and can be used as the walls of a basement.
- They can be used in constructing buildings on a slope.
- With strip foundations, it is possible to provide better insulation for the floors of a house.
The Disadvantages of Strip Footings
There are a number of disadvantages of using strip footings as well:
- They are resource-intensive: it requires a lot of materials to build strip footings.
- They require additional waterproofing and are not initially frost resistant.
- If the building in construction is massive, the placement of these foundations will require a greater amount of earthworks.
- This type of foundation should not be used on heaving soils (clays) or unstable grounds.