How to Fix a Broken Floor Joist
Improper Notching Causes Problems
Notches can compromise the strength of floor joists, some notches are acceptable, depending on their location and are dictated by the International Residential Code [IRC]. Here’s a good rule of thumb:
- Notches should be no deeper than 1/6 the depth of the joist.
- Notches at the end of the joist should be no deeper than 1/4 the depth.
- Limit the length of notches to 1/3 of the joist’s depth.
Not only did this aggressive notching doom this joist, it affects the structural integrity of the floor system above. To make matters worse there was a refrigerator above our joist and the floor was sagging a bit!
A severely, cracked, or sagging floor joist can get worse over time, causing the floor above it to slope or become unleveled.