Alabama Contractors License Practice Exam

What is the minimum size of a footing for a two-story light-frame construction home on soil with a 2,000 psf load bearing value?

1. 12 in

2. 15 in

3. 17 in

4. 23 in

The correct answer is: 12 in

The minimum size of a footing for a two-story light-frame construction home is determined by the load-bearing capacity of the soil and the loads that the structure will impose on it. Given that the soil has a load-bearing value of 2,000 pounds per square foot (psf), this figure plays a critical role in sizing the footings accordingly. The typical rule of thumb for residential structures is that the footings should spread the load sufficiently over the soil to ensure stability and prevent settling. For light-frame construction, which is generally lighter and imposes less load than heavier construction types, footings can often be smaller. Footings around 12 inches wide are often adequate for this type of construction and soil condition, assuming that the load calculations do not surpass the soil’s bearing capacity. The 12-inch width allows for proper load distribution, ensuring that the weight of the structure does not exceed the soil’s capacity to hold it. Other sizes such as 15 inches, 17 inches, and 23 inches might be applicable in more stringent load conditions or different soil types, but in this context, for a standard two-story home on soil with a 2,000 psf load bearing value, a 12-inch footing is often sufficient and