Where the hygrothermal environments in adjacent interior spaces are sufficiently different, an air barrier system is required to control the airflow between the spaces in order to maintain the different environments. Examples of such adjacent spaces include skating arenas adjoining swimming pools, and industrial office spaces adjoining industrial production spaces.
An air barrier system is also required in building assemblies in contact with the ground to control the ingress of radon and other soil gases, such as methane.
In addition to an air barrier system, other measures may be required in certain regions of Canada to reduce the radon concentration to a level below the guideline specified by Health Canada. Further information on protection from radon ingress can be found in:
- “Radon: A Guide for Canadian Homeowners” (CMHC/HC),
- “Guide for Radon Measurements in Public Buildings (Schools, Hospitals, Care Facilities, Detention Centres)” (HC), and
- EPA 625/R-92/016, “Radon Prevention in the Design and Construction of Schools and Other Large Buildings.”