Crawl space encapsulation in the Birmingham area typically costs $3 to $10 per square foot, about $3,000 to $15,000 for most homes, with a crawl space dehumidifier adding $1,000 to $3,000 installed, according to HomeGuide's January 2026 encapsulation guide. Encapsulation covers the dirt and walls with a sealed vapor retarder and closes the vents so humid outdoor air stops condensing on the framing. NOAA's 1991 to 2020 normals give the Birmingham airport station about 65 days a year at or above 90 degrees, and that summer air is what soaks an open crawl space. BDry Alabama covers its encapsulation systems for the life of the structure against material and workmanship defects, and the free inspection sets the exact price.
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These are typical installed ranges from HomeGuide's January 2026 national guide, not quotes. Square footage, how easy the space is to get into, and whether water, mold or rot has to be handled first set your price, which comes from a free inspection.
| Crawl space scope | Typical installed range |
|---|---|
| Full encapsulation, 1,000 sq ft | $3,000 to $10,000 |
| Full encapsulation, 1,500 sq ft | $4,500 to $15,000 |
| Full encapsulation, 2,000 sq ft | $6,000 to $20,000 |
| Vapor barrier only, installed | $2 to $4 per sq ft |
| Crawl space dehumidifier, installed | $1,000 to $3,000 |
| Interior crawl space drain with pump | $800 to $3,000 |
| Mold remediation before sealing | $1,500 to $4,000 |
Figures are typical ranges and vary by project. Your free estimate is exact.
BDry Alabama measures your project and gives you a clear written estimate at no cost.
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An open crawl space breathes outdoor air, and around Birmingham that air is hot and wet for months. NOAA's 1991 to 2020 climate normals for the Birmingham airport station show July averaging a high of 91.0 degrees and a low of 72.1, with about 65 days a year at or above 90. When that air slides under the house and meets ductwork, pipes and framing cooled by the air conditioning above, it condenses. Insulation sags, joists darken, and the musty smell rises into the rooms. Encapsulation stops the exchange: the ground is covered, the vents are closed, and a dehumidifier holds the space in a steady range all summer.
Crawl space encapsulation in the Birmingham area typically costs $3 to $10 per square foot, or $3,000 to $15,000 total, according to HomeGuide's January 2026 guide. By size, HomeGuide lists 1,000 square feet at $3,000 to $10,000, 1,500 at $4,500 to $15,000 and 2,000 at $6,000 to $20,000. Add ons change the total: a crawl space dehumidifier runs $1,000 to $3,000 installed, an interior drain with a pump $800 to $3,000, and mold remediation before sealing $1,500 to $4,000. A dry, open crawl space lands near the low end; a wet, tight one near the high end. BDry Alabama measures the space at a free inspection and gives you one written price for the full scope.
A vapor barrier is a liner laid on the dirt. Encapsulation seals the whole space. The International Residential Code, Section R408.3, describes what a sealed crawl space needs: exposed earth "covered with a continuous Class I vapor retarder," joints that "overlap by 6 inches" and are sealed or taped, and edges that extend at least 6 inches up the stem wall and are sealed to it, plus a way to condition or dehumidify the air. HomeGuide's 2026 data puts a liner alone at $2 to $4 per square foot installed and full encapsulation at $3 to $10. The liner slows ground moisture; the sealed, dried envelope is what stops condensation on the framing.
Only as part of a complete system. Closing vents over bare, damp dirt traps moisture and makes the problem worse. The International Residential Code, Section R408.3, says the usual ventilation openings are not required when the ground is covered with a sealed Class I vapor retarder and the space gets conditioned air, continuous exhaust at 1 cubic foot per minute for each 50 square feet, or, in the 2021 edition, dehumidification sized at 70 pints a day per 1,000 square feet. In a climate with about 65 days a year at or above 90 degrees at the Birmingham airport station under NOAA's normals, open vents bring in more water than they carry out. BDry Alabama seals the vents when it seals the rest.
In this climate, usually. The liner stops moisture from the ground, but air still carries water, and the EPA's mold guide says to "keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity." A dehumidifier built for a crawl space holds the space in that range through a July where NOAA's 1991 to 2020 normals put the Birmingham airport's average low at 72.1 degrees. HomeGuide's January 2026 guide puts one at $1,000 to $3,000 installed. It needs a filter change and a drain check, both part of the BDry Elite visits. Dehumidifiers are covered by their manufacturer's warranty.
Not until the water is handled. Sealing a liner over standing water traps it against the framing. The usual order is to fix the outside drainage, add an interior drain and a sump if groundwater still collects, and then encapsulate, and HomeGuide's January 2026 guide puts an interior crawl space drain with a pump at $800 to $3,000. Water that appears only after heavy rain is common here: NOAA's 1991 to 2020 normals give the Birmingham airport station 17.7 days a year with an inch of rain or more. BDry Alabama prices the drainage and the encapsulation together so the steps happen in the right order.
It gets treated before the space is sealed, never sealed in. Mold in a crawl space means the wood has stayed damp, and the EPA notes that materials dried within 24 to 48 hours usually will not grow mold, so staying damp for months is what produces it. HomeGuide's January 2026 guide puts crawl space mold remediation at $1,500 to $4,000 on average. Treatment removes the growth; encapsulation and a dehumidifier remove the moisture that fed it. Note that BDry Alabama's warranties exclude mold, mildew and organic growth, so the treatment is priced as its own line and the humidity is checked on every maintenance visit.
Both usually trace back to moisture under the house. Damp air softens joists and girders until they deflect, and hardwood above a humid crawl space absorbs moisture from below and cups. BDry Alabama installs adjustable steel support posts on footings under sagging beams, and HomeGuide's February 2026 guide puts sistering a damaged joist at $150 to $325 per joist. Floor support systems carry a two year warranty. Supports fix the sag; drying the crawl space fixes the cause, which is why the supports go in first and the liner is sealed after. The EPA's guidance to keep humidity below 60 percent applies under the floor as much as in the rooms above it.
It helps, but it is not pest control. A sealed crawl space covers the bare soil that insects travel across, closes the vents and gaps that give animals an easy way in, and removes the damp conditions many pests look for. A clean liner also makes activity easier to spot on a routine check. Termite treatment and wildlife removal are separate services, and BDry Alabama's liner warranty covers tears but excludes damage from wildlife or misuse. Keeping the crawl space door closed and the vents sealed is the simplest way to keep animals from tearing the liner, and the BDry Elite visits check the encapsulation for damage twice a year.
Encapsulation systems are covered for the life of the structure against material and workmanship defects, and crawl space liners are warranted against tears, excluding wildlife damage or misuse. Dehumidifiers and sump pumps are covered by their manufacturers' warranties. If you sell, BDry Alabama must be notified within 60 days of the sale and the new owner receives two years of coverage, with extended coverage possible after an inspection. The warranty can be voided if the installed system is altered without approval or if access for service is refused. A buyer's inspector will open the crawl space hatch, and a sealed space with paperwork answers the question.
Check the humidity and the equipment twice a year. The BDry Elite Silver plan, at $349 a year or $35 a month, covers two visits that inspect the encapsulation, measure the humidity, change or clean the dehumidifier filter, service the sump pump and check the discharge line, and it includes a free humidity gauge so you can read the level yourself. The Gold plan, at $595 a year or $59 a month, adds an annual digital foundation scan, an annual air quality test for mold spores and allergens, two gutter cleanings and free warranty transfers. The target is the EPA's range, below 60 percent and ideally 30 to 50.
Usually it removes the source. A musty smell upstairs in a house over a crawl space most often comes from damp soil, wet insulation or mold on the framing below, and air from the crawl space moves up into the living space through gaps around pipes, wires and ducts. Sealing the ground and the vents and drying the air takes away the damp conditions the odor comes from. The EPA's target, humidity "below 60 percent (ideally between 30 and 50 percent)," is the number to hold, and the dehumidifier is what holds it through a Birmingham summer. If mold is already growing, it is treated first; sealing does not remove growth that is already there.
Often, and where the insulation goes matters. Old fiberglass batts between the floor joists tend to absorb moisture, sag and fall in a humid crawl space, so they are usually removed when the space is sealed, at about $1 to $2 per square foot per HomeGuide's January 2026 guide. In a sealed crawl space the insulation typically moves to the walls. HomeGuide puts crawl space insulation at $1.00 to $4.50 per square foot or $500 to $3,700 total, with rigid foam board on the walls at $1.20 to $3.70 per square foot and closed cell spray foam at $2.00 to $5.00. The International Residential Code, Section R408.3, ties its exhaust and conditioned air options for an unvented crawl space to perimeter walls insulated to the energy code.
No. Crawl space repair fixes damage that is already there: wood rot in sills and joists, beams that have sagged, supports that were spaced too far apart. Encapsulation prevents the next round by sealing the ground, the walls and the vents and drying the air. In most damp crawl spaces the repair comes first and the encapsulation follows, so the new liner protects sound framing. HomeGuide's January 2026 guide puts crawl space repairs at $500 to $8,000 depending on the issue, and its February 2026 sagging floor guide puts sistering a joist at $150 to $325. BDry Alabama does both, with adjustable steel floor supports and wood rot repair ahead of the liner.
Call BDry Alabama at 205 942 1976 or send the form, Monday through Friday from 7 in the morning to 6 in the evening. At the visit we go under the house, photograph the ground, the insulation, the joists and any water, measure the humidity, and show you the pictures. You get the scope in the order it should happen, with one written price and financing options if you want them, and there is no pressure to decide that day. HomeGuide's January 2026 guide puts full encapsulation at $3 to $10 per square foot, so measuring the space is the first step to a real number.
Crawl space encapsulation seals the dirt floor, foundation walls and vents under a house with a heavy plastic liner to keep ground moisture out, and the typical cost table on this page puts a 1,000 sq ft job at $3,000 to $10,000. You likely need it if you see standing water, damp or sagging joists, musty odors upstairs, or mold on the wood. The EPA notes that materials dried within 24 to 48 hours usually will not grow mold, so wood that stays damp for months is the warning sign. Size moves the price most: a 2,000 sq ft crawl space runs $6,000 to $20,000 on the same table. Adding a dehumidifier ($1,000 to $3,000), an interior drain with pump ($800 to $3,000) or mold remediation before sealing ($1,500 to $4,000) pushes a job toward the top tier, while a vapor barrier alone at $2 to $4 per sq ft suits a crawl space with no water or mold. BDry Alabama does this work with its own crews.
Full crawl space encapsulation in Alabama typically runs $3,000 to $10,000 for a 1,000 square foot crawl space and $6,000 to $20,000 for 2,000 square feet, according to the typical cost table on this page. Size sets the baseline, and a vapor barrier alone costs $2 to $4 per square foot installed. A crawl space dehumidifier adds $1,000 to $3,000, an interior drain with a pump adds $800 to $3,000 where water collects, and mold remediation before sealing adds $1,500 to $4,000. Mold shows the wood has stayed damp for months, because the EPA notes that materials dried within 24 to 48 hours usually will not grow mold. A dry, open crawl space with good clearance lands near the low end of each range. Standing water, low clearance, rotted joists or mold push a project toward the top. BDry Alabama sends its own crews to do the encapsulation after measuring the space and checking it for moisture.
A musty smell and moisture in a crawl space mean the wood and soil have stayed damp for weeks or months, and the EPA notes that materials dried within 24 to 48 hours usually will not grow mold. The usual sources are a bare dirt floor, humid air entering through vents, and pooling rainwater. The EPA recommends keeping relative humidity below 60 percent, ideally 30 to 50 percent. The fix scales with the problem, per the typical cost table on this page: a vapor barrier alone runs $2 to $4 per sq ft, a crawl space dehumidifier $1,000 to $3,000 installed, and full encapsulation of 1,500 sq ft $4,500 to $15,000. Standing water adds an interior drain with pump at $800 to $3,000, and visible mold adds remediation at $1,500 to $4,000 before sealing. The International Residential Code requires a sealed crawl space's vapor retarder to overlap seams by 6 inches and run 6 inches up the walls. BDry Alabama's own crews handle the drainage, dehumidification and encapsulation.
BDry Alabama
1490 Valley Drive, Bessemer, AL 35022
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