What are installed in crawlspaces to prevent moisture from the ground from entering the home?

Vapor retarders are specifically designed to prevent moisture from the ground in crawlspaces from entering the home. When installed properly, they create a barrier that significantly reduces the amount of water vapor that can permeate through floors, walls, and other structures, helping to maintain a drier environment within the crawlspace. This is essential for preventing mold growth, wood rot, and other moisture-related issues that can compromise the integrity of the building and affect indoor air quality.

Drainage systems are important for managing excess water, but they do not serve the same purpose as vapor retarders in terms of blocking moisture vapor from the ground. Dehumidifiers can assist in reducing moisture levels in crawlspaces but rely on active systems to remove humidity rather than providing a preventative barrier. Insulation batts contribute to thermal performance and can impact moisture control to some extent, but they are not designed primarily to prevent moisture ingress from the ground. Therefore, vapor retarders stand out as the most effective solution for addressing moisture transfer in crawlspaces.