Intent 1:
To limit the probability of:
- excessive spacing between wythes, which could lead to:
- compromised ability of wythes to act as a single, structural
element, or
- buckling of wall ties under compressive loads due to
lateral loads from wind or earthquakes, or
- an inadequate width of cavities, which could lead to
extruded mortar bridging the cavity, which could lead to water crossing
the cavity and penetrating the interior wythes by capillary action,
which could lead to the deterioration of the interior wythes.
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.