1. OH1
  2. OS2
  3. OP2
  4. OH4
  5. OS3


OH1 Indoor Conditions


[F20-OH1.1,OH1.2,OH1.3]Applies to elements that support or are part of an environmental separator.


Intent 1:

To limit the probability of inadequate vertical support, which could lead to cracking of cavity walls.

Where exterior masonry walls support an environmental separator or act as one, this is to limit the probability of the excessive deformation, displacement or failure of required environmental separation elements.

This is to limit the probability of:

  • condensation,
  • precipitation ingress,
  • moisture ingress,
  • excessive heat transfer,
  • pollutant ingress, or
  • compromised thermal performance of components intended to resist heat transfer.

This is to limit the probability of:

  • an inadequate control of temperatures in interior spaces, drafts, relative humidity or water accumulation,
  • the generation of pollutants from biological growth or from materials that become unstable on wetting, or
  • deterioration, which could lead to further compromised integrity of environmental separators.

This is to limit the probability of:

  • negative effects on the air quality of indoor spaces,
  • the inadequate thermal comfort of persons, and
  • contact with moisture.

This is to limit the probability of harm to persons.

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