Intent 1:
To limit the probability of localized over-stressing
and crushing of wood plates under concentrated roof or floor loads
transmitted through framing elements, which could lead to inadequate
load distribution, which could lead to over-stressing of hollow masonry
units, which could lead to cracking of such units.
Where masonry units support or are part of an environmental separator,
this is to limit the probability of:
- excessive moisture transfer through masonry units, or
- deformation or cracking, which could lead to the displacement
or failure of required environmental separation elements.
This is to limit the probability of:
- 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:
- an inadequate control of temperatures in 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 exempt situations where another means of distributing
roof and floor loads is provided from the application of Sentence 9.20.8.1.(1).