Crawl space encapsulation cost calculatorCrawl space encapsulation is a liner, seals, and usually a dryer under the house, sold as one job. The liner is a vapour barrier on the soil and often up the walls. Sealing closes vents and holes that let outside air in. Insulation, a drain, a dehumidifier, old-insulation removal, and mould remediation are separate published prices. Figures are published US cost ranges from HomeGuide's 2026 guide, not quotes. Your contractor's price will differ.
HomeGuide's installed range is $3–$10 per square foot, and a typical total is $3,000–$15,000. The size table is that rate written out: 1,000 square feet is $3,000–$10,000, 1,500 is $4,500–$15,000, 2,000 is $6,000–$20,000, 2,500 is $7,500–$25,000, and 3,000 is $9,000–$30,000. This calculator uses $3–$10 per square foot as the vapour-barrier line, then adds only the lines you tick.
How the total is built
The first line is area times $3 to area times $10. A 6 mil sheet does not add a second materials charge, because the installed range already prices the job. Eight, 10, 12, or 20 mil adds only the materials-table gap versus 6 mil. Six mil material is $0.30–$0.35 per square foot. Twenty mil is $0.60–$0.70, so the extra is $0.30–$0.35 per square foot, not a new installed rate.
Other rows are added only when selected. Sealing vents and holes is $150–$450. Inspection is $100–$250. Insulation installation is $500–$3,700. A note of $1.00–$4.50 per square foot for insulation is not a second line. Old insulation removal is $1–$2 per square foot. Drainage, a French or perimeter drain with trenching, gravel, pipe, and a pump, is $800–$3,000. Dehumidifier installation is $1,000–$3,500. Mould remediation is $15–$30 per square foot. The guide also lists $1,500–$4,000 as a typical crawl-space mould job; this line uses the per-square-foot band because you typed an area.
Each endpoint is rounded half up to the cent after that line, and the total after the sum. Cost per square foot divides the total by your area. The sanity check repeats area times $3 to area times $10, so optional work that leaves the typical band is visible. A quote you type is compared with the total. It is not a benchmark.
Why the range is wide
$3 and $10 per square foot are both in the same guide. HomeGuide says labour is the dominant share, and that accessibility, clearance, and local labour rates move the price. Cleaning or repairs, if required, are $500–$8,000 before a liner goes down. This calculator does not apply a state multiplier. No regional figure is verified here.
What the barrier thickness changes
Per square foot, 6 mil material is $0.30–$0.35, 8 mil is $0.35–$0.40, 10 mil is $0.40–$0.50, 12 mil is $0.50–$0.60, and 20 mil is $0.60–$0.70. The 1,200 square foot rolls are $360–$420, $420–$480, $480–$600, $600–$720, and $720–$840. A vapour barrier with installation is about $2–$4 per square foot, and vapour-barrier installation is listed at $1,200–$4,000. Those describe the barrier job. They are not added on top of the $3–$10 range, which would count the same work twice. The guide does not publish a lifespan, so a thicker sheet is a materials difference, not a warranty term.
When a drain or a dehumidifier belongs on the quote
Tick a dehumidifier only when the proposal includes a machine. Installation is $1,000–$3,500 and stays off until selected. Tick drainage when the quote names a French or perimeter drain, published at $800–$3,000 with trenching, gravel, pipe, and a pump. A liner is not priced here as a substitute for that drain. The dehumidifier guide keeps the machine off the per-square-foot band.
What to check before you sign
Match the proposal to the rows. Which mil is specified? Is sealing the $150–$450 line? Is inspection the $100–$250 visit? Is insulation the $500–$3,700 installation, and is removal quoted at $1–$2 per square foot? Mould at $15–$30 per square foot is $18,000–$36,000 on 1,200 square feet, larger than the encapsulation line, and it dominates the total. The $1,500–$4,000 typical mould range is not a cap. Cleaning or repairs, if required, are $500–$8,000. Minor foundation cracks are $250–$800, and major foundation repair is $4,500–$20,000. Those two repairs are not form fields. Ask who handles mould, what the warranty covers, and whether the machine and the drain sit inside the price.
Signs the space needs a look
Standing water, a musty smell upstairs, fallen insulation, visible mould, and open vents are reasons to price the inspection at $100–$250 before a liner. With no extras, 1,000 square feet uses the $3,000–$10,000 sanity check, 1,500 is $4,500–$15,000, and 2,000 is $6,000–$20,000. A dehumidifier adds up to $3,500. See the per-square-foot guide and the DIY guide.
A roof system is a different home improvement: the solar cost calculator. A purchase that has not closed uses the closing cost calculator for published Florida, Texas, and California rates. Neither prices a crawl space.
Questions
How much does crawl space encapsulation cost per square foot?
HomeGuide's 2026 guide publishes an installed encapsulation range of $3–$10 per square foot. On 1,000 square feet with a 6 mil barrier and no added lines, this calculator uses that range as $3,000–$10,000. A thicker barrier adds only the materials-table difference versus 6 mil. Sealing, inspection, insulation, drainage, a dehumidifier, removal, and mould remediation are extra lines, so a job with those selected can sit above $10 per square foot.
How much for a 1,000 / 1,500 / 2,000 sq ft crawl space?
HomeGuide's size table matches $3–$10 per square foot: 1,000 square feet is $3,000–$10,000, 1,500 square feet is $4,500–$15,000, and 2,000 square feet is $6,000–$20,000. Those bands are the sanity check on this page. They are the typical installed range, not a quote, and they do not include every optional line.
Does encapsulation include a dehumidifier?
Not in this calculator unless you select it. HomeGuide lists dehumidifier installation as its own line at $1,000–$3,500. The $3–$10 per square foot installed range is separate. Ask the contractor whether a machine, a drain, and a warranty are in the proposal or priced beside it.
Is crawl space encapsulation worth it?
This page does not publish a savings, energy, or repair-avoided figure, so it cannot say a job pays for itself. Worth is a comparison you make: the itemised range against a written quote, and the moisture, mould, or standing water you can see. HomeGuide's typical total is $3,000–$15,000. A quote far outside the lines you selected is a reason to ask what else is in the price.
Can I do it myself?
HomeGuide notes that labour is the dominant share of the job. A materials-only 6 mil barrier is published at $0.30–$0.35 per square foot, or $360–$420 for a 1,200 square foot roll, while installation of a vapour barrier is published at $1,200–$4,000 and about $2–$4 per square foot with installation. This site does not publish a DIY total. Mould remediation and drainage are the lines most people should not treat as a weekend materials purchase.
How long does encapsulation last?
HomeGuide's 2026 cost guide, the only source used for the figures on this page, does not state a lifespan in years. This calculator does not invent one. A thicker sheet is published at a higher materials price — 20 mil is $0.60–$0.70 per square foot, against $0.30–$0.35 for 6 mil — but that price difference is not a durability warranty.