Sistering Floor Joists: When It Works and When It Doesn't

Sistering Floor Joists: When It Works and When It Doesn't

Koray Bozkurt, PE, PMP
Published on: 23/10/2026

Sistering floor joists fixes cracked or over-drilled joists, not failed supports. The IRC limits holes to 1/3 of joist depth. Learn when you need an engineer.

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