To repair broken floor joists, make new boards with extra space to create board braces, and bolt the braces next to the broken joists. You need boards that have the same width and thickness as the old joists. You also need a saw, drill, bolts, nuts and a tape measure to complete this project.Continue Reading
Make sure that there is no structural damage to the foundation before fixing the joists, and contact an inspector or contractor if necessary.
Cut the board a minimum of 6 inches longer on each end for proper support. Measure the broken board, and make the necessary cuts.
Drill two holes on each end of the board, and leave around 2 inches of space from the end of the bolt size. Ensure that the bolt has enough length to bolt through the new and damaged boards.
Pinpoint the location of the holes on the broken joists using the new board. Mark the points, and drill the holes. If the boards are shifting, bolt the new brace board on one side of the existing joist, and tighten the piece using the nuts. Get someone to help you push the old boards evenly as you bolt the opposite end of each new board. Repeat the entire process for other broken joists.