Encapsulating a crawl space is one of the best things you can do if you live in the Southeast. With humid air and high temperatures for much of the year and open (vented) crawl space is one of the worst building ideas. In fact, some states have changed the code to not allow this type of building.
What is encapsulation? Encapsulation is sealing off your walls, floors and vents from outside air and controlling the interior closed past by other means. This is typically done by using a dehumidifier but can be a modified part of your home A/C system, a plenum type system or even a air exchange between your home and the crawl space.
When encapsulating a crawl space is very important to use the right materials. Code requires:
- Class 1 Vapor Barrier (this is not plastic but has to meet the requirements of moisture permeability).
- Overlapped and taped seams (can’t be laid down loose).
- Sealed to the walls
- Closed off Vents
- Some air control mechanism (commonly a dehumidifier but can be others)
When choosing a contractor make sure he understands the difference between a vapor barrier and encapsulation. Keep in mind that the better encapsulation job, the less a dehumidifier will have to work – ultimately costing less to maintain your crawl space. Additionally – research dehumidifiers to find the right size and energy efficiency. Not all units are sized for your home and some can cost you hundreds of dollars a year to operate.