Massachusetts Unrestricted Construction Supervisor License Practice Test

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

1. A. 1.5 inches in depth, 3.5 inches long (not in middle third)

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

3. C. 2 inches in depth at the bottom of the joist (not in middle third)

4. D. 2 inches in depth, 4 inches long (not in middle third)

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

When evaluating the options for notching a 12-foot long 2x12 floor joist, it's important to consider the structural integrity and code requirements for notching. Notching a joist can impact its strength and load-bearing capacity. Building codes, including those set by the National Design Specification for Wood Construction, lay out specific guidelines for notching wood members. Generally, the depth and location of the notch are critical factors in determining what is allowable. In the given scenario, the choice indicating 3.5 inches in depth at the end of the member is prohibited. This is because notches at the ends of a joist can severely compromise the load distribution and structural integrity. Typically, the maximum depth allowed for a notch is limited to one-quarter of the joist's depth, and such notches should be avoided in areas where they could lead to significant points of weakness, such as the ends or the middle third of the member. The other choices provide notching dimensions that are either acceptable or not in the critical middle third region and do not exceed the generally permitted depth for notches in joists, thereby maintaining structural integrity. This makes the option that involves notching full depth at the end of the member the only one that is