There are currently two main types of crawl space vapor barriers on the market. Humidity in your crawl space can lead to mold, mildew, and bug problems. Also, the rooms above or adjacent to your crawl space can feel stuffy and begin to smell. To solve these problems, you can install a vapor barrier.
Flat Lay Vapor Barriers
Flat lay vapor barriers are the simpler of the two types discussed in this article and also the least expensive. The flat lay option is viable only if there is no sidewall water problem underneath the house. In the flat lay method, the material only covers the floor of the crawl space, and each section should overlap by at least 12 inches. Special tapes and stakes are required to make sure all the pieces are secure and won't move around after installation.
Crawl Space Encapsulation System
The crawl space encapsulation system takes the covering material all the way up to the walls to prevent all moisture penetration. No air is allowed to leak in from the outside. Special sealants are used for permanence and small allowances are made for pest control examinations. You can also have a water watch alarm installed, which will alert you if there is an internal water pipe failure.