Back9.19.1.3.(2)

ATTRIBUTION:

Functional Statement:

F62

To facilitate the dissipation of water and moisture from the building.

F51

To maintain appropriate air and surface temperatures.

Objective:

OH1.1, OH1.2, OH1.3

 

APPLICATION:

Clear air space between insulation baffles and the underside of the roof sheathing at the junction with exterior walls, in attic and sloped roof assemblies, in buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9], where insulation is installed above the ceiling and below the roof sheathing.

INTENT:

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.
To exempt junctions of sloped roofs and exterior walls where preformed baffles are installed from the minimum clear air space dimensions specified in Sentence 9.19.1.3.(1), based on the demonstrated effectiveness of a reduced unobstructed space provided by insulation baffles.

ATTRIBUTION:

Functional Statement:

F62

To facilitate the dissipation of water and moisture from the building.

F51

To maintain appropriate air and surface temperatures.

Objective:

OS2.3

 

APPLICATION:

Clear air space between insulation baffles and the underside of the roof sheathing at the junction with exterior walls, in attic and sloped roof assemblies, in buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9], where insulation is installed above the ceiling and below the roof sheathing.

INTENT:

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 deterioration, which could lead to compromised structural integrity of attic or roof assemblies or of elements protected by attic or roof assemblies, which could lead to harm to persons.
To exempt junctions of sloped roofs and exterior walls where preformed baffles are installed from the minimum clear air space dimensions specified in Sentence 9.19.1.3.(1), based on the demonstrated effectiveness of a reduced unobstructed space provided by insulation baffles.