This article provides step by step instructions and pictures on how to make structural repairs by sistering floor joists alongside weak joists.
Sistered sistering floor joists.
Framing lumber is the typical.
How to sister a floor joist.
Properly sistering floor joists is very important and should not be rushed to save time.
So a 2 foot extension will be 4 feet sistered to the existing joist with appropriate fasteners 3 nails in a w pattern every 12.
Sistering joists means beefing them up with additional material.
Doing so strengthens weak joists and can help straighten sagging joists.
If you have sagging cracked or twisted joists which can happen in older houses this project will provide the extra support the floor needs.