Crawl Space Encapsulation & Repair Cost Calculator
Estimate crawl space encapsulation, drain, mold and joist repair costs from published per-unit rates, with the source shown next to every answer.
Pick the work, enter the one measurement that actually drives its price, and you get the range those figures imply. There is no email gate and nothing is sent anywhere - the arithmetic happens in your browser.
It covers four kinds of work and not the other two, for a specific reason: these are the ones somebody publishes a per-unit price for. Where the only published figure is "per home", multiplying it by anything would be inventing a number.
Roughly the footprint of the house over the crawl space. The outside dimensions of the ground floor are close enough for a planning number.
Before you start
What each calculation needs
Four calculations, one measurement each. The rate is the published per-unit range the tool multiplies, and the last column is what it returns at the quantity the tool opens with.
| Work | What you measure | Published rate | Example quantity | Planning range |
|---|---|---|---|---|
| Encapsulation cost | square feet | $2.76 - $7.36 per sq ft of crawl space, North Carolina | 1,200 square feet | $3,312 - $8,832 |
| Mold Remediation cost | square feet affected | $12 - $28 per sq ft of affected area | 100 square feet affected | $1,200 - $2,800 |
| Waterproofing & Drainage cost | linear feet | $40 - $100 per linear foot, interior installation | 60 linear feet | $2,400 - $6,000 |
| Crawl Space Repair cost | joists | $150 - $325 per joist | 4 joists | $600 - $1,300 |
How to take each measurement
- Encapsulation: Roughly the footprint of the house over the crawl space. The outside dimensions of the ground floor are close enough for a planning number.
- Mold Remediation: The surface actually showing growth - a run of joists, a patch of subfloor - not the size of the crawl space. This is the single most common thing to get wrong when comparing quotes.
- Waterproofing & Drainage: The run being drained, which is often one or two walls rather than the whole perimeter. A quote for the full perimeter should be able to say why it needs it.
- Crawl Space Repair: Sistering bolts a sound new joist alongside a damaged one. Replacing a joist outright, or a girder, is priced separately and far higher - see the full table on the structural repair cost page.
Read this next to the number
What pushes a job toward the top of its range
Every one of these genuinely moves a price, and not one of them has a published figure attached. Rather than invent percentages, the calculator leaves them out of the arithmetic and puts them here.
- Clearance under about 18 inches, where the whole job is done lying down.
- An access hatch too small to pass materials and debris through.
- Wet fallen insulation or a failed older liner that has to be bagged and hauled out first.
- Ground that is still taking on water, which has to be dealt with before anything is sealed.
- Ductwork, plumbing or wiring in the way of the work.
- A crawl space small enough that the crew’s setup and travel dominate the price.
What this cannot see
A number built from one measurement is a budgeting range, not an estimate. It is blind to rotted joists nobody has found yet, a foundation crack, a discharge line that has to run a long way to daylight, an active termite problem, and asbestos or vermiculite in older insulation. Any one of those changes the picture, which is exactly why a real quote follows somebody getting under the house.
It also cannot add up. The four calculations are separate pieces of work priced by separate sources; running all four and summing them does not produce a project price, because it omits mobilization, access, disposal and overhead. The full cost guide and the methodology set out what these figures are and what they are not.
Prices on this page are general ranges gathered from published sources, not a quote. What a job actually costs depends on the specifics of the job and who does the work. Only a quote from a qualified contractor who has seen the job is a real price.
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How to read it
Questions about the calculator
Why does the calculator give a range instead of one price?
Because the sources publish ranges. Each result is the low and the high published per-unit figure multiplied by the quantity you enter. Narrowing that to a single number would mean inventing where in the range your job falls.
Can I add the results together to price a whole project?
No. Each calculation is a separate piece of work priced by a separate source, and a real project also carries mobilization, access, disposal and overhead that none of them include. Use each result on its own, as a check on the matching line of a written quote.
Why does it only cover four kinds of work?
Those are the jobs a named source publishes a per-unit price for. Where the only published figure is per home, multiplying it by a measurement would be making a number up, so those jobs are left to the tables in the cost guide.
Do I have to give an email address or phone number to see the result?
No. The arithmetic runs in your browser, nothing is sent anywhere, and the range appears as soon as you enter a quantity.
How close is a planning range to a real quote?
It is only as good as your measurement and the published rate behind it. It cannot see rotted framing, a long discharge run, tight access or anything else a contractor finds under the house, which is why a written quote after an inspection replaces it.
Request a Free Inspection
Tell us what you are seeing and we will follow up to schedule your free crawl space inspection. No obligation to hire.
No cost to submit a request, and no obligation to hire.