Code allows cantilever spans of 24 inches for every 1 inch of beam depth. For a 9 inch beam, what is the allowable cantilever span?

Code allows cantilever spans of 24 inches for every 1 inch of beam depth. For a 9 inch beam, what is the allowable cantilever span?

• A. 12'
• B. 24'
• C. 30'
• D. 18'

Answer: (D)

The allowable cantilever is directly proportional to the beam depth, at 24 inches per 1 inch of depth. For a 9-inch beam, multiply: 9 × 24 = 216 inches, which equals 18 feet. So the cantilever span can be 18 feet. (Other values would require different beam depths to match those spans.)

The allowable cantilever is directly proportional to the beam depth, at 24 inches per 1 inch of depth. For a 9-inch beam, multiply: 9 × 24 = 216 inches, which equals 18 feet. So the cantilever span can be 18 feet. (Other values would require different beam depths to match those spans.)