Sistering To Repair Improperly Notched Floor Joists

A failed joist may minimally lead to a sagging floor or in extreme cases the collapse of a home.

Sistering to repair improperly notched floor joists.

When the sagging joists are level apply a generous bead of construction adhesive to the existing joist. Sistering joists means beefing them up with additional material. Framing lumber is the typical. Driving 16d common nails in old hard wood is difficult.

Doing so strengthens weak joists and can help straighten sagging joists. A hole is often a round or square opening fully contained on all 4 sides within a joist. Then attach the sister joist using three 16d common nails driven every 16 in. Take some extra time and jack the damaged area up so that the new lumber doesn t need to be.

In some cases a plumber or. A notch is generally a 3 sided cut in the joist where the 4th side is open at the top bottom or end of the joist. However doing this does not fix the slant that the floor has taken since the old joists got damaged. Her floor joists were notched by someone installing electrical cabling in the middle of the span on the bottom of the joist.

But it s usually best to run the sister joist over the entire span. Floor joists constructed from large dimension lumber bear the weight of the structure above so notching them isn t recommended. How to sister a floor joist.