The short answer
HomeGuide puts crawl space repair at $500–$8,000, depending on the issue. That is not a vague answer, it is an honest one: the phrase covers a roll of plastic on the ground and a rebuilt girder, and those are not the same job. Work that includes clearing out rot and old insulation averages $2,500–$8,000.
So the useful question is not what crawl space repair costs. It is which of these you are being quoted.
What each job costs
| Job | Typical cost | Source | Goes deeper |
|---|---|---|---|
| Crawl space inspection | $100–$250 | HomeGuide | inspection cost |
| Sistering a floor joist | $150–$325 per joist | HomeGuide | joist and girder repair |
| Replacing a floor joist | $350–$1,000 per joist | HomeGuide | joist and girder repair |
| Sagging floor, structural fix | $4,500–$20,000+ (structural) | HomeGuide | sagging floors |
| Sagging floor, as a Charlotte add-on | $1,500-$9,800 | Angi | sagging floors |
| Repair including rot and old materials | $2,500–$8,000 | HomeGuide | foundation repair |
| Vapor barrier, installed | $1,200–$4,000 | HomeGuide | encapsulation |
| Interior drain, French or perimeter | $800–$3,000 | HomeGuide | — |
| Dehumidifier, installed | $1,000–$3,000 | HomeGuide | moisture control |
| Mold remediation | $1,500–$4,000 | HomeGuide | — |
| Full encapsulation | $3,000–$15,000 | HomeGuide | encapsulation cost |
| Permit | $100–$250 | This Old House | — |
Call to schedule an inspection
Structural or moisture: that is the fork
Almost every crawl space quote is one of two families, and they price differently.
Structural work holds the house up: supports, joists, girders, shimming. It is priced one piece at a time, so the count is the total. Two honest quotes can differ by thousands because one found more pieces than the other.
Moisture work changes the air and the ground: a barrier, a drain, a dehumidifier, or all of it as encapsulation. It is priced more like a system, by area and equipment.
Charlotte pushes houses toward the second. In July the normal here is 67.7 degrees F dew point, and any surface in the crawl space cooler than that collects condensation. Humid outside air moving through a vented crawl space is not drying it in July; it is the reason the wood is wet.
The two things that move the number most
How much framing is involved. One sistered joist and a dozen are the same line item at twelve times the price. This is why a quote that gives a total without a count cannot be compared with one that gives both.
Whether the cause is in the price. Replacing wood that rotted and leaving the water that rotted it is a repair with a timer on it. Ask what the plan does about the water, and whether that is inside the total or a second quote.
Access matters too, and it is the one you cannot change: a crawl space you can sit up in and one you can barely slide into are different days of labour for identical work.
Call to schedule an inspection
Two questions worth asking on the call
Before anyone comes out, two answers will tell you what kind of quote to expect.
- Is the floor sloping toward an outside wall, or toward the middle of the house? They point at different parts of the structure, and the second usually means the centre beam or its supports.
- Is there standing water, damp ground, or just humid air? Standing water is a drainage question before it is a repair question, and a quote that starts with the barrier may be solving the wrong half.
Want someone to look at it? Call to schedule an inspection. Work is done by independent local contractors, and the contractor serving your area sets the price after the visit.