Crawl space insulation in the Wilmington area typically costs $1,500–$4,000, or roughly $1.50–$3.50 per square foot installed. Wall insulation in a sealed crawl space usually costs less than subfloor batts across the same footprint, because there is less area to cover.
Cost by approach
The two approaches are not interchangeable, and they do not cost the same. Which one applies is decided by whether your crawl space is vented or sealed — not by budget.
- Subfloor batts, vented crawl space — $1.50–$2.50/sq ft of floor area
- Rigid board to perimeter walls, sealed crawl space — $1,200–$3,000 for a typical perimeter
- Rim and band joist air sealing — $400–$900, and the best value item on this list
- Removal and disposal of failed existing insulation — $400–$1,200
Why removal is so often on the quote
Most Wilmington crawl spaces built before the 2000s have fiberglass batts stapled to the subfloor, and in this climate a large share of them have come down. Wet, fallen fiberglass has no remaining R-value and holds moisture against the framing, so it has to come out before anything goes in.
If a quote for insulation does not mention removal and your crawl space has existing batts, ask what happens to them.
The item that pays for itself fastest
Air sealing the rim and band joist is consistently the highest-value line on a crawl space insulation quote and the most commonly omitted. It is a small area, it takes a fraction of the labour of a full floor, and it addresses the single largest air leakage path between the crawl space and the living space above.
The bottom line
Budget $1,500–$4,000, expect removal of failed batts to be part of it in most older Wilmington homes, and make sure the rim joist is included whatever else is.
For a number against your own crawl space, use the cost estimator, or call (910) 886-2018 and we will come and measure it.