What is the maximum percentage of stud depth that a notch may occupy in exterior or load-bearing interior wall studs?

The correct answer is 25%. According to building codes and plumbing regulations, notches in studs are intended to maintain the structural integrity of walls while allowing for the installation of piping and wiring. The maximum amount that a notch can occupy is limited to 25% of the stud's depth in exterior or load-bearing interior wall studs. This limitation helps ensure that sufficient material remains in the stud to support the loads applied to the wall, thus preventing structural failure.

It's important to adhere to this specification during construction or remodeling to maintain safety and compliance with building codes designed to protect the structural integrity of buildings. In situations where a greater notch is necessary, alternative methods such as using holes or considering special framing solutions should be explored to avoid compromising the wall's strength.