Intent 1:
To limit the probability of:
- inadequate support for roof joists and rafters, which
could lead to an inability to resist expected gravity loads, which
could lead to crushing, or
- insufficient area for fastening, which could lead to
an inability to resist expected lateral or wind-uplift loads, which
could lead to the separation of roofs from walls.
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,
- moisture 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.