Crawl space encapsulation in Dothan
Encapsulation shuts a crawl space off from muggy outdoor air and damp ground. Here's what that looks like in a Wiregrass home.
Encapsulating a crawl space means turning it from a space that breathes outdoor air into one that's sealed and dried. The International Residential Code calls this an unvented crawl space. Vents get closed, a liner goes over the ground and up the walls, and a moisture-control method keeps the air dry.
What does Dothan's code require?
Dothan enforces the 2021 International Residential Code. Under Section R408.3, a crawl space can go without vents when the exposed earth is covered by a continuous Class I vapor retarder, with joints overlapped 6 inches and sealed or taped and edges carried at least 6 inches up the stem wall and sealed there. The code also requires one of these moisture-control approaches:
- Continuous exhaust ventilation at 1 cubic foot per minute for each 50 square feet of crawl space floor
- Conditioned air supplied at that same rate, with a return air path
- Use as a supply plenum, where the code allows it
- A dehumidifier sized to remove 70 pints of water a day for every 1,000 square feet
Steps in a typical job
- Inspect. Check for standing water, damaged wood, plumbing leaks, termite activity and old insulation.
- Handle water. Gutters, grading, or an interior drain and sump where water gets in.
- Clean out. Remove old plastic, fallen batts and construction debris.
- Seal. Close vents, the access opening and penetrations around pipes and wires.
- Line. Lay the liner, tape the seams and run it up walls and piers.
- Dry. Install the dehumidifier or other moisture-control method.
Licenses and permits
A full encapsulation often costs more than $10,000, which is the point at which Alabama requires a Home Builders Licensure Board license for residential work. Inside Dothan, ask the company whether a permit is needed from Building Inspection Services, particularly for new electrical circuits or HVAC changes.
What affects the price?
- Size of the crawl space and how much room there is to work
- Liner thickness and wall coverage
- Debris and old insulation removal
- Any drainage work
- The moisture-control equipment chosen
The crawl space company sets the price after it has inspected and measured the space under your house. We don't quote prices, and any figure you hear before someone has looked underneath is a rough guess.
Where we connect you with help
Common questions
Does an encapsulated crawl space need a dehumidifier?
It needs some approved moisture control under IRC R408.3. A dehumidifier is one option; continuous exhaust and conditioned supply air are others.
Will encapsulation stop water from coming in?
No. Water that runs or seeps in has to be handled with gutters, grading or a drain and sump. Encapsulation controls humidity and ground moisture.
Related services
More background: Dothan crawl space guide.
Musty air, wet insulation or a floor that's lost its footing?
Call and get connected with a crawl space company that works in Dothan and the Wiregrass.