Floor joist repair costs depend on what failed and what caused it. A soft spot, bounce, dip, or slope may come from a single damaged joist, several wet joists, a weak beam, bad posts, poor bearing, subfloor damage, or moisture below the house.
Use this calculator to get a planning range before comparing contractor quotes. It is not a contractor bid. It helps show whether the likely cost is only joist repair or part of a larger crawl-space support problem.
Estimate your floor joist repair cost
How this estimate works
The calculator starts with the number of joists affected and the repair scope, then adjusts the planning range for access, moisture, subfloor damage, beam or post involvement, floor correction, cleanup, inspection, and regional labor conditions.
When floor joist repair needs diagnosis first
Joist repair should not be treated as a simple sistering job when the crawl space is wet, the beam below is weak, posts are leaning, pads are soft, the subfloor is damaged, or the floor needs leveling. Those conditions change both the repair and the price.
What changes the price most
- How many joists are affected
- Whether joists are sistered, replaced, or engineered
- Whether subfloor damage is included
- Whether the beam, post, pier, or pad below is also failing
- Whether water or rot caused the joist damage
- How tight the crawl-space access is
- Whether floor correction or staged leveling is needed
Do not compare joist repair quotes by price alone
One quote may include a few sistered joists. Another may include subfloor repair, beam correction, posts, pads, leveling, moisture control, cleanup, and an engineer’s recommendation. Those are not the same repair.