• Rigid barrier systems
  • Rigid components such as drywall, wood components, sheathing and certain rigid foam insulation, are combined with gaskets, sealants, and approved tapes to form the air barrier system

• Membrane barrier system
  • Flexible membranes, compatible sealants, and approved tapes create the air barrier system

The system used will determine where the air barrier and vapour retarder will be placed in the envelope systems, and what materials will be used. The air barrier can always be placed anywhere within the building envelope, but the vapour retarder must be on the warm side of the building envelope, which is determined by where the insulation is installed in the building envelope. Remember that any approach used will require all control layers to be present.