1. OH1
  2. OS2
  3. OH2


OS2 Structural Safety


[F61,F42-OS2.3]Applies where access is from the exterior or an unheated enclosed space.


Intent 1:

To limit the probability of openings in environmental separators, which could lead to:

  • the ingress of precipitation,
  • the ingress of insects or vermin,
  • excessive heat transfer,
  • compromised thermal performance of components intended to provide resistance to heat transfer,
  • condensation,
  • the accumulation of moisture or the ingress of water backed up by ice dams,
  • drafts, or
  • the ingress of pollutants from adjacent attic or roof spaces.

This is to limit the probability of deterioration, which could lead to compromised structural integrity of building components, which could lead to harm to persons.

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