If a floor joist is 12 inches deep, the maximum notch depth is

If a floor joist is 12 inches deep, the maximum notch depth is

• A. 1 inch
• B. 1 1/2 inches
• C. 2 inches
• D. 3 inches

Answer: (C)

Notching floor joists is allowed only up to a limited depth to keep the member strong under load. The rule is that a notch can be no deeper than one-sixth of the joist’s depth. With a 12-inch-deep joist, one-sixth equals 2 inches, so the maximum notch depth is 2 inches. Notches deeper than that would weaken the joist and reduce its bending capacity. If you need to pass more through, you’d look for alternative routing or reinforcement.

Notching floor joists is allowed only up to a limited depth to keep the member strong under load. The rule is that a notch can be no deeper than one-sixth of the joist’s depth. With a 12-inch-deep joist, one-sixth equals 2 inches, so the maximum notch depth is 2 inches. Notches deeper than that would weaken the joist and reduce its bending capacity. If you need to pass more through, you’d look for alternative routing or reinforcement.