Which of the following is NOT a requirement for digging trench-type footings?

When considering the requirements for digging trench-type footings, the correct answer indicates that "level bottom" is not strictly necessary as a formal requirement. While having a level bottom can certainly facilitate proper drainage and ensure that the footing is evenly supported, it is more critical to focus on the other aspects such as correct location, width, and depth.

The correct location ensures that the footings are placed in the right position according to the construction plans, which is vital for the structural integrity of the building. Correct width is essential for providing adequate support and stability to the structure that will be built. Correct depth is also necessary to reach solid soil and prevent heaving or settling, especially in areas that may be affected by frost or shifting soil conditions.

In contrast, while a level bottom is beneficial, it is often more about achieving a good construction practice rather than a strict requirement. It may suffice to have the bottom be fairly level as long as the footings meet the criteria for location, width, and depth. Thus, this makes "level bottom" the aspect that is not a strict requirement for digging trench-type footings.