Vaporex is made from a Kraft paper saturated with asphalt. This product sheds water, prevents moisture and air from penetrating but does not impede the passage of water vapour and therefore minimize the condensation of such vapour permitting walls to breathe. This product may content recycled paper fibre. USES: Vaporex is used on the outside walls of wood frame buildings, under the external finish, as a secondary protective barrier against entry of wind and moisture. It may also be applied beneath wood siding, stucco, brick, aluminum, vinyl or any other type of siding