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.
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.
Intent 2:
To limit the application of Sentence (1) for constructions where support for increased roof
loads has to be provided.