This standard applies to flexible sheet material made from low-density polyethylene, primarily intended for use in building construction to retard the passage of moisture and water vapor. The purpose of this standard is to control the thickness of polyethylene sheet material and to provide a basis for its procurement.

Material to this standard may also be suitable for use as a vapor barrier material for use in building construction, provided that it meets requirements contained in CAN2-51.33-M Vapor Barrier, Sheet, for Use in Building Construction.

The polyethylene material is not intended for use in packaging applications or other uses where special grease or oil resistance or flame resistance may be required.