1. OH1
  2. OS2


OH1 Indoor Conditions



Intent 1:

To limit the probability of inadequate airflow through the vented space, which could lead to:

  • condensation in the space, or
  • the formation of ice dams, which could lead to the ingress of water.

This is to limit the probability of:

  • compromised thermal performance of components intended to provide resistance to heat transfer, which could lead to an inadequate control of the temperature of interior spaces,
  • water accumulation in interior spaces or an inadequate control of relative humidity,
  • the generation of pollutants from biological growth or from materials that become unstable on wetting, or
  • deterioration, which could lead to compromised integrity of ceilings acting as 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.

Intent 2:

To exempt junctions of sloped roofs and exterior walls where preformed baffles are installed from the minimum clear air space dimensions specified in Sentence, based on the demonstrated effectiveness of a reduced unobstructed space provided by insulation baffles.

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