Un-Vented Subspaces - Ground Cover

Remove all vegetation and organic material from area to be covered

Remove all debris that can cause injury or puncture ground vapor retarder (e.g., nails, glass, sheet metal screws, etc.)

Select a 6-mil minimum ground vapor retarder of 0.1 perm or less

Cover all exposed soil

Extend ground vapor retarder a minimum of 6" up all foundation walls and piers, but do not install in contact with non-treated structural wood

The ground vapor retarder will not interfere with the established drainage pattern (e.g., to sump pits, French drains, etc.)

Overlap seams a minimum of 12" with reverse or upslope lapping technique

For wall to floor connection, install the wall vapor retarder under the ground vapor retarder

Seal all seams and connections to foundations and piers air tight with a durable, compatible, sealant

Mechanically attach ground vapor retarder to foundation and piers where practical

Fasten ground vapor retarder to ground with durable fasteners or ballast(s) when installed on sloping ground, or space is accessed for routine maintenance or storage

Seal all penetrations in the ground vapor retarder with a compatible sealant

Install a durable (minimum of 10-year service life), easily seen sign, sized a minimum of 8.5"x 11" at each access to the space

Sign shall minimally include the following items:

Warning to prohibit storage of hazardous and flammable materials

Caution not to damage the ground vapor retarder, air barrier, insulation, and mechanical components specific to the space

Immediate repairs are needed in the case of damage