Massachusetts Construction Supervisor License (CSL) Practice Test

Which of the following notching techniques is NOT allowed for a 12-foot long 2x12 floor joist?

1. 1.5 inches in depth, 3.5 inches long

2. 3.5 inches in depth at the end of the member

3. 2 inches in depth at the bottom of the joist

4. 2 inches in depth, 4 inches long

The correct answer is: 3.5 inches in depth at the end of the member

The choice indicating 3.5 inches in depth at the end of the member is not allowed because it affects the structural integrity of the floor joist significantly. Floor joists are designed to carry loads, and notching the end of a joist to that depth effectively removes a substantial portion of its material, compromising its strength and load-carrying capacity. In the context of floor joist construction, the allowable notching techniques are carefully defined to ensure that the structural performance is maintained. The techniques that are acceptable, such as 1.5 inches in depth and 3.5 inches long, or 2 inches in depth, 4 inches long, maintain a balance between not affecting the joist's strength and still allowing some modifications for practical construction needs. Therefore, any notch that removes too much material, especially at critical areas like the end of the joist, exceeds the limits set by building codes, leading to potential structural weaknesses.