Intent 1:
To limit the probability of the failure to adjust
spans for undersized joists, rafters, lintels or beams, which could
lead to inadequate strength or rigidity, which could lead to an inability
to resist expected gravity, lateral or wind uplift loads.
Where lumber supports or is used in an environmental separator,
this is to limit the probability of compromised performance of the
building envelope, which could lead to:
- condensation,
- precipitation ingress, or
- compromised thermal performance of components intended
to provide resistance to heat transfer.
This is to limit the probability of:
- an inadequate control of indoor air and surface temperatures,
drafts, relative humidity, or water accumulation,
- the generation of pollutants from biological growth
or from materials that become unstable upon 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.