Back9.23.13.8.(3)

ATTRIBUTION:

Functional Statement:

F20

To support and withstand expected loads and forces.

F22

To limit movement under expected loads and forces.

Objective:

OS2.1, OS2.3, OS2.5, OS2.3, OS2.5

 

APPLICATION:

Minimum sizes and maximum spans of ridge beams that are 38 mm by 140 mm or larger, and that are supported every 1.2 m or less, in wood-frame constructions to which Section 9.23. applies [see Sentence 9.23.1.1.(1) for application of Section 9.23.].

INTENT:

To supersede the requirements for ridge beam support stated in Sentence (2), in constructions where spans of ridge beams are limited and appropriate support conditions are provided.
This is to limit the probability of compromised structural integrity, which could lead to:
  • the structural collapse of wood-frame construction,
  • where roof and ceiling framing members support required elements of environmental separators, the excessive deformation, displacement or failure of these elements, which could lead to deterioration, which could lead to further compromised structural integrity of roofs or environmental separators, or
  • where roof and ceiling framing members support assemblies exposed to the exterior, excessive water ingress, which could lead to deterioration.
This is to limit the probability of harm to persons.

ATTRIBUTION:

Functional Statement:

F20

To support and withstand expected loads and forces.

F22

To limit movement under expected loads and forces.

Objective:

OP2.1, OP2.3, OP2.5, OP2.3, OP2.4, OP2.5

 

APPLICATION:

Minimum sizes and maximum spans of ridge beams that are 38 mm by 140 mm or larger, and that are supported every 1.2 m or less, in wood-frame constructions to which Section 9.23. applies [see Sentence 9.23.1.1.(1) for application of Section 9.23.].

INTENT:

To supersede the requirements for ridge beam support stated in Sentence (2), in constructions where spans of ridge beams are limited and appropriate support conditions are provided.
This is to limit the probability of compromised structural integrity, which could lead to:
  • the structural collapse of wood-frame construction,
  • where roof and ceiling framing members support required elements of environmental separators, the excessive deformation, displacement or failure of these elements, which could lead to deterioration, which could lead to further compromised structural integrity of roofs or environmental separators, or
  • where roof and ceiling framing members support assemblies exposed to the exterior, excessive water ingress, which could lead to deterioration.
This is to limit the probability of damage to the building.

ATTRIBUTION:

Functional Statement:

F20

To support and withstand expected loads and forces.

F22

To limit movement under expected loads and forces.

Objective:

OH1.1, OH1.2, OH1.3

 

APPLICATION:

Minimum sizes and maximum spans of ridge beams that are 38 mm by 140 mm or larger, and that are supported every 1.2 m or less, in wood-frame constructions to which Section 9.23. applies [see Sentence 9.23.1.1.(1) for application of Section 9.23.].

INTENT:

To supersede the requirements for ridge beam support stated in Sentence (2), in constructions where spans of ridge beams are limited and appropriate support conditions are provided.
Where wood-frame construction supports or is part of an environmental separator, this is to limit the probability of the displacement or failure of required environmental separation elements, which could lead to:
  • condensation,
  • precipitation ingress,
  • excessive heat transfer,
  • pollutant ingress, or
  • compromised thermal performance of components intended to resist heat transfer.
This is to limit the probability of:
  • inadequate control of temperatures of 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.

ATTRIBUTION:

Functional Statement:

F20

To support and withstand expected loads and forces.

F22

To limit movement under expected loads and forces.

Objective:

OS1.2

 

APPLICATION:

Minimum sizes and maximum spans of ridge beams that are 38 mm by 140 mm or larger, and that are supported every 1.2 m or less, in wood-frame constructions to which Section 9.23. applies [see Sentence 9.23.1.1.(1) for application of Section 9.23.].

INTENT:

To supersede the requirements for ridge beam support stated in Sentence (2)), in constructions where spans of ridge beams are limited and appropriate support conditions are provided.
Where assemblies are required to provide fire resistance, this is to limit the probability of compromised fire resistance of the assembly, which could lead to harm to persons.

ATTRIBUTION:

Functional Statement:

F22

To limit movement under expected loads and forces.

Objective:

OS3.7

 

APPLICATION:

Minimum sizes and maximum spans of ridge beams that are 38 mm by 140 mm or larger, and that are supported every 1.2 m or less, in wood-frame constructions to which Section 9.23. applies [see Sentence 9.23.1.1.(1) for application of Section 9.23.].

INTENT:

To supersede the requirements for ridge beam support stated in Sentence (2), in constructions where spans of ridge beams are limited and appropriate support conditions are provided.
This is to limit the probability of the excessive deflection or deformation of supporting members, which could lead to compromised operation of doors or windows required for egress in an emergency, which could lead to harm to persons.