Michigan Residential Builders License Practice Test

Which type of footing is used over soil with poor load-bearing capacity and generally covers the entire footprint of the structure?

1. Strip footing

2. Mat footing

3. Continuous footing

4. Spread footing

The correct answer is: Mat footing

The type of footing used over soil with poor load-bearing capacity, which covers the entire footprint of the structure, is a mat footing. This type of footing is designed to distribute the load of the structure over a large area, effectively reducing the pressure exerted on the underlying soil. By covering the entire footprint, mat footings help mitigate the risk of settlement or failure in soils that cannot support high loads concentrated in smaller areas. Mat footings are particularly beneficial in situations where the soil conditions are not favorable, such as in marshy or clay-heavy environments where traditional footings might sink or settle unevenly. They provide a stable base for the structure, which is crucial for maintaining integrity and preventing structural issues down the line. In contrast, strip footings are typically used for supporting foundations of walls and are not designed to cover the entire footprint, which limits their effectiveness in challenging soil conditions. Continuous footings also support walls but are generally not large enough to distribute weight over the entire foundation area. Spread footings, while they do distribute weight, are smaller and not intended for entire structures, making them less suitable for scenarios with poor load-bearing capacity.