A notch must be placed in a ceiling joist of nominal size 2 x 10 that spans 12 feet 8 inches. What is the maximum notch that can be placed on the top, 2 feet from the exterior wall?

The maximum notch that can be placed in a ceiling joist is dependent on the size and span of the joist, as well as the location of the notch. In this case, the joist is a nominal 2 x 10 (which has actual dimensions roughly 1.5 x 9.25 inches) and spans 12 feet 8 inches.

For ceiling joists, the codes typically allow for notching in certain locations, with restrictions based on their dimensions to maintain their structural integrity. The maximum allowable notch depth is based on the total depth of the joist. Generally, the maximum notch depth should not exceed one-quarter of the joist's depth when located within a certain distance from the point of support.

In this scenario, since the notch is located 2 feet from the exterior wall, which is typically closer to a supporting wall than the midpoint of the span, this is crucial. The maximum notch permissible at this location would typically be about 1/8 of the total depth of the joist. For a nominal 2 x 10, the depth is approximately 9.25 inches. Therefore, the maximum notch at this location would be approximately 1.54 inches (9.25 inches / 4