910 Crawl Space Pros prices crawl space encapsulation in Wilmington between $4,200 and $14,000, with a typical project landing near $5,500. That works out at roughly $3–$9 per square foot. The single biggest variable is whether the crawl space takes on groundwater, because drainage has to be solved before anything is sealed.
Cost by component
Encapsulation is a system, and the price depends on which pieces your crawl space actually needs. A dry, clean crawl space may need only the first three lines below. A wet or moldy one needs more, and no honest quote can skip them. Component-level detail lives on the vapor barrier installation and dehumidifier installation pages.
| Component | What it buys | Typical cost |
|---|---|---|
| Vapor barrier (reinforced 12–20 mil) | The core component. Reinforced liner sealed across the floor, piers and walls — not the 6 mil builder sheet. | $1,500 – $4,000 |
| Vent sealing | Closing and sealing foundation vents to convert the space to a closed crawl space. | $300 – $1,000 |
| Dehumidifier (installed) | A unit sized to the cubic footage, with a condensate pump and drain line. | $1,200 – $2,500 |
| Drainage + sump pump — only if needed | Perimeter drain and sump. Only where the crawl space takes on water — and it goes in before the liner. | $1,500 – $5,000 |
| Mold removal & wood treatment — only if needed | Only where there is active growth. Remove, treat the framing, and dry before sealing. | $500 – $4,000 |
| Full encapsulation (combined) | Wilmington-area range. A dry crawl space needs liner, vent sealing and a dehumidifier; one that takes on groundwater needs drainage first, which is most of the spread. | $4,200 – $14,000 |
Cost by crawl space size
Square footage sets the liner and dehumidifier sizing, but clearance changes the labour more than area does. Below roughly 24 inches, everything takes longer — materials have to be dragged in rather than carried, and installers work lying down.
| Crawl space size | Typical total | Notes |
|---|---|---|
| Under 800 sq ft | $4,200 – $6,000 | Small footprint, good clearance, no water |
| 800 – 1,500 sq ft | $5,000 – $9,000 | The most common Wilmington range |
| 1,500 – 2,500 sq ft | $7,500 – $12,000 | Larger runs of liner and a bigger dehumidifier |
| Over 2,500 sq ft, or low clearance | $10,000 – $14,000 | Labour hours dominate below about 24 inches of clearance |
Why two quotes differ by thousands
Most of the gap is not labour rate. It is scope that is present in one quote and silently absent from the other. Four things account for nearly all of it:
- Liner specification. A 6 mil unreinforced builder sheet costs a fraction of reinforced 12–20 mil meeting ASTM E1745, and it will not survive being crawled on. Ask for the mil rating and whether it is reinforced.
- Whether the vents are sealed or merely covered. Covering is minutes. Sealing and detailing is hours.
- Whether groundwater is addressed. A quote that omits drainage on a crawl space that floods is cheaper because it is going to fail.
- Dehumidifier sizing. A small unit costs less and never reaches target in a space it was not sized for.
What changes the price on a Cape Fear property
The regional water table is the recurring one. Much of Wilmington sits low over sandy soil that drains fast at the surface and slowly beneath it, and the area takes roughly 57 inches of rain a year. Where the assessment finds standing water or a high-water mark, perimeter drainage and a sump are quoted first at $1,500 – $5,000, and that single line is most of the difference between a $5,000 project and a $12,000 one.
Older housing stock is the other. Downtown and through Forest Hills, pre-1940 homes on brick piers have open perimeter walls and low clearance — more surfaces to terminate the liner against, and slower going underneath.
The bottom line
Budget $4,200 – $14,000 for a full encapsulation in the Wilmington area, expect around $5,500 for a typical dry crawl space, and treat any quote materially below $4,200 as a prompt to ask what has been left out. For a number against your own square footage, use the cost estimator — or call (910) 886-2018 and we will come and measure it.