Sistered Sistering Floor 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.
Sistered sistering floor joists. Sistering joists means beefing them up with additional material. 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. The section being inserted and sistered should be twice as long as the cantilever. Since this is a repair of a faulty or damaged floor joist it is imperative to do this project correctly and there are a few big mistakes to avoid.
Properly sistering floor joists is very important and should not be rushed to save time. Framing lumber is the typical. Doing so strengthens weak joists and can help straighten sagging joists.