How to Repair Floor Joists With Dry Rot
- 1). Measure the length of the floor joist that requires a sister joint. Take the measurement to a lumberyard and have a piece of lumber ripped to the correct size.
- 2). Lift the sister joint into position and clamp it to the rotted piece of wood. Place a nail at each side of the joist to attach the new piece to the old joist.
- 3). Add a 6d nail every 4 inches, except where the old joist is rotted.
- 4). Set a jigsaw to the depth of the rotted piece of wood and cut out the rotted area. Make the cut as square as possible. Measure the area.
- 5). Cut a piece of lumber the same size as the piece you took out. Add wood glue to one side and pound it in place with a hammer. Add a 4d nail on each corner to keep it stuck in place.