End-notching of a joist is limited to what fraction of the joist depth?

End-notching of a joist is limited to what fraction of the joist depth?

• A. Notch Depth Cannot Exceed One Third Of Joist Depth
• B. Notch Depth Cannot Exceed One Quarter Of Joist Depth
• C. Notch Depth Cannot Exceed One Half Of Joist Depth
• D. Notch Depth Cannot Exceed One Fourth Of Joist Depth

Answer: (D)

End-notching cuts into the joist’s cross-section, weakening its bending strength where it bears on supports. Limiting the notch to one quarter of the joist depth preserves enough wood around the cut to carry loads and resist bending and shear, reducing the risk of cracking or failure near the support. If you need more room, use other solutions (like routing around the joist or drilling holes away from the edge) rather than making a deeper notch. For an example, an 8-inch-deep joist can have at most a 2-inch notch.

End-notching cuts into the joist’s cross-section, weakening its bending strength where it bears on supports. Limiting the notch to one quarter of the joist depth preserves enough wood around the cut to carry loads and resist bending and shear, reducing the risk of cracking or failure near the support. If you need more room, use other solutions (like routing around the joist or drilling holes away from the edge) rather than making a deeper notch. For an example, an 8-inch-deep joist can have at most a 2-inch notch.