Which statement about holes bored through a joist is true?

Which statement about holes bored through a joist is true?

• A. Holes should be located near the edges
• B. Holes should be limited to the center third of the joist
• C. Holes should be bored through full height
• D. Holes should never be bored

Answer: (B)

Passing services through a joist is allowed, but you want to keep the hole in a part of the joist that preserves bending strength. Placing the bore in the center third of the joist depth keeps it away from the stressed top and bottom fibers, so there’s still enough remaining wood around the hole to resist bending and potential splits. Drilling through the full height would remove material across the entire depth, weakening the member more, while holes near the edges undermine the outer fibers that carry the greatest bending stress. Holes aren’t prohibited altogether; they’re acceptable as long as they stay within these interior limits and are sized appropriately.

Passing services through a joist is allowed, but you want to keep the hole in a part of the joist that preserves bending strength. Placing the bore in the center third of the joist depth keeps it away from the stressed top and bottom fibers, so there’s still enough remaining wood around the hole to resist bending and potential splits. Drilling through the full height would remove material across the entire depth, weakening the member more, while holes near the edges undermine the outer fibers that carry the greatest bending stress. Holes aren’t prohibited altogether; they’re acceptable as long as they stay within these interior limits and are sized appropriately.