Back9.19.1.2.(2)

ATTRIBUTION:

Functional Statement:

F51

To maintain appropriate air and surface temperatures.

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:

Vent areas for attic or roof spaces, 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, and
  • the roof slope is less than 1 in 6 or the roof is constructed with roof joists.

INTENT:

To limit the probability of an inadequate vent area for roofs, which could lead to:
  • condensation,
  • the accumulation of moisture, or
  • the formation of ice dams.
This is to limit the probability of:
  • the ingress of water, or
  • compromised thermal performance of components intended to provide resistance to heat transfer.
This is to limit the probability of:
  • an inadequate control of the temperature of interior spaces or relative humidity,
  • the generation of pollutants from biological growth or from materials that become unstable on wetting,
  • deterioration, which could lead to compromised integrity of ceilings acting as environmental separators, or
  • water accumulation in interior spaces.
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 supersede the requirement stated in Sentence 9.19.1.2.(1), where the air pressure differential from eave to ridge is limited or where the space below the sheathing is interrupted by framing.

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:

Vent areas for attic or roof spaces, 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, and
  • the roof slope is less than 1 in 6 or the roof is constructed with roof joists.

INTENT:

To limit the probability of an inadequate vent area for roofs, which could lead to:
  • condensation,
  • the accumulation of moisture, or
  • the formation of ice dams.
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 supersede the requirement stated in Sentence 9.19.1.2.(1), where the air pressure differential from eave to ridge is limited or where the space below the sheathing is interrupted by framing.