Intent 1:
To limit the probability of inadequate strength,
which could lead to an inability to resist bending stress imposed
by struts or dwarf walls in addition to other expected gravity and
lateral loads, which could lead to:
- the failure of the roof or of the ceiling joists, or
- the excessive deflection of the roof, which could lead
to the opening of joints.
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.
Intent 2:
To limit the application of Sentence (1) for constructions where support for increased roof
loads has to be provided.