See what sealing your crawl space should cost before a contractor quotes you. Enter its size and answer a few questions. You get a low-to-high price, with each part shown apart. No sign-up needed.
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| Encapsulation | — |
| Dehumidifier, installed | — |
| Mold removal | — |
| Drain and pump | — |
| Old insulation removal | — |
National prices, not your city's. Tight or hard-to-reach crawl spaces, permits, pest problems and structural repairs cost extra. Based on HomeGuide, Angi cost data, updated October 2026. See sources.
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Price per square foot of crawl space floor, with the total for a 1,000 sq ft crawl space. Dehumidifier, mold and drainage are not included.
| Job | What it includes | Cost / sq ft | 1,000 sq ft |
|---|---|---|---|
| Basic — vapor barrier on the floor, seal the vents | Heavy plastic barrier on the ground, vents and gaps sealed | $2.00–$4.00 | $2,000–$4,000 |
| Full — barrier on floor and walls, insulation, sealed vents | Barrier up the walls, wall insulation, vents and rim sealed, light cleaning | $3.00–$10.00 | $3,000–$10,000 |
Contractors price encapsulation by the square foot of crawl space floor. A basic job runs $2 to $4 per square foot. A full job, with the walls covered and insulated, runs $3 to $10. We multiply your size by that rate. A dehumidifier, mold removal and a drain add the typical amounts shown in the sources below. We round to the nearest $100.
Your real price depends on your city, how much room there is to work, and what the crew finds down there. Get at least three written quotes. If the floor above is sagging or the walls are cracked, see the foundation repair cost calculator, or find contractors in your city.
Angi puts the average at $5,500, with most jobs between $5,000 and $15,000. HomeGuide reports $3,000 to $15,000 in total, depending on the size and condition of the crawl space.
Angi says basic encapsulation costs $2 to $4 per square foot, and more complete jobs $3 to $10. HomeGuide reports $3 to $10 per square foot. A 1,000 sq ft crawl space costs about $3,000 to $10,000, says HomeGuide.
In a humid area, yes, says HomeGuide: the barrier stops ground moisture, but humidity can still build up. A crawl space dehumidifier costs $1,000 to $3,000 installed.
It is fixed first. Angi lists mold work at $1,000 to $3,500, and HomeGuide puts crawl space mold removal at $1,500 to $4,000. HomeGuide prices an interior crawl space drain at $800 to $3,000.
HomeGuide says most homeowners recover the cost in 7 to 10 years through lower energy bills, fewer repairs and higher home value, and that it can cut energy bills by 10% to 30%.
National figures. We do not adjust for your region. Rates checked October 2026.