How To Repair A Cracked Floor Joist. The first step is to jack up the floor frame from below using a floor jack and a temporary beam placed across the damaged joist and two or more neighboring joists. You should go down there with a tape and if possible a digital camera.
Measure the size of joists the span and the centers. Usually the new piece of lumber spans the length of the old one. If the broken joist has shifted a bit you will first need to install one side of the brace board you have made by bolting it onto the old joist and securing it with nuts.
Notches should be no deeper than 16 the depth of the joist.
Slip an old-work metal joist hanger onto the end of the joist. I recently had to repair a broken floor joist that had cracked. The first step is to jack up the floor frame from below using a floor jack and a temporary beam placed across the damaged joist and two or more neighboring joists. Usually the new piece of lumber spans the length of the old one.
