Back9.23.15.5.(1)

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:

Maximum width, end support and end joints for lumber roof sheathing, 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 limit the probability of:
  • excessive width, which could lead to excessive shrinkage, which could lead to:
    • buckling or tearing of roofing, or
    • excessively wide gaps between boards, which could lead to puncturing of roofing,
  • unsupported end joints, which could lead to an inability to resist point loads from foot traffic, which could lead to differential deflection of unsupported sheathing board ends, which could lead to damage to roofing, and
  • aligned end joints, which could lead to discontinuity in the roof structure, which could lead to an inability to resist expected lateral or gravity loads, which could lead to excessive deflection, which could lead to damage to roofing.
This is to limit the probability of compromised structural integrity, which could lead to:
  • the structural collapse of wood-frame construction, or
  • precipitation ingress, which could lead to deterioration, which could lead to further compromised structural integrity of the roof.
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, OP2.5

 

APPLICATION:

Maximum width, end support and end joints for lumber roof sheathing, 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 limit the probability of:
  • excessive width, which could lead to excessive shrinkage, which could lead to:
    • buckling or tearing of roofing, or
    • excessively wide gaps between boards, which could lead to puncturing of roofing,
  • unsupported end joints, which could lead to an inability to resist point loads from foot traffic, which could lead to differential deflection of unsupported sheathing board ends, which could lead to damage to roofing, and
  • aligned end joints, which could lead to discontinuity in the roof structure, which could lead to an inability to resist expected lateral or gravity loads, which could lead to excessive deflection, which could lead to damage to roofing.
This is to limit the probability of compromised structural integrity, which could lead to:
  • the structural collapse of wood-frame construction, or
  • precipitation ingress, which could lead to deterioration, which could lead to further compromised structural integrity of the roof.
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:

Maximum width, end support and end joints for lumber roof sheathing, 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 limit the probability of:
  • excessive width, which could lead to excessive shrinkage, which could lead to:
    • buckling or tearing of roofing, or
    • excessively wide gaps between boards, which could lead to puncturing of roofing,
  • unsupported end joints, which could lead to an inability to resist point loads from foot traffic, which could lead to differential deflection of unsupported sheathing board ends, which could lead to damage to roofing, and
  • aligned end joints, which could lead to discontinuity in the roof structure, which could lead to an inability to resist expected lateral or gravity loads, which could lead to excessive deflection, which could lead to damage to roofing.
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:
  • precipitation ingress, or
  • compromised thermal performance of components intended to resist heat transfer.
This is to limit the probability of:
  • an inadequate control of temperatures of interior spaces 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:

Maximum width, end support and end joints for lumber roof sheathing, 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 limit the probability of:
  • excessive width, which could lead to excessive shrinkage, which could lead to:
    • buckling or tearing of roofing, or
    • excessively wide gaps between boards, which could lead to puncturing of roofing,
  • unsupported end joints, which could lead to an inability to resist point loads from foot traffic, which could lead to differential deflection of unsupported sheathing board ends, which could lead to damage to roofing, and
  • aligned end joints, which could lead to discontinuity in the roof structure, which could lead to an inability to resist expected lateral or gravity loads, which could lead to excessive deflection, which could lead to damage to roofing.
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.