Residential Building Inspector Practice Exam

Notches along the length of a solid lumber joist shall not exceed what fraction of the depth of the member?

1. 1/4

2. 1/5

3. 1/6

4. 1/8

The correct answer is: 1/6

The correct answer is based on the guidelines established for structural integrity and safety when modifying solid lumber joists. Notches should be limited to a specific fraction of the depth of the lumber joist to prevent weakening the structural member. In this case, a notch cannot exceed 1/6 of the depth of the member. When notches are made in a lumber joist, they can significantly affect the load-bearing capacity and the overall stability of the structure. A depth limitation of 1/6 helps ensure that the joist maintains enough strength to support loads and resist bending or failure. This standard provides a balance between making necessary adjustments for utilities or other installations while also preserving the structural integrity of the joist. By following this guideline, builders and inspectors can help ensure that structures remain safe and functional, reducing the risk of potential failures related to improper modifications of lumber joists.