What is the minimum thickness of a vapor retarder required?

The minimum thickness of a vapor retarder required is 6 mil. This specification is often dictated by building codes and industry standards to provide an adequate barrier against moisture infiltration in residential construction. A vapor retarder helps prevent moisture from the ground or exterior from entering the building envelope, which can lead to mold growth and structural damage.

Using 6 mil plastic sheeting is standard, as it strikes a balance between flexibility and effectiveness. It is thick enough to prevent moisture penetration while still being manageable for installation. A retarder of insufficient thickness might not perform adequately, allowing moisture to pass through and compromising the structural integrity and indoor air quality of the building.

Understanding this requirement is essential for ensuring the durability and comfort of a residential structure, as moisture management is a critical aspect of good building practices.