Intent 1:
To limit the probability of the entrapment of moisture
inside closed building envelopes, which could lead to:
- excessive post-installation shrinkage and warping,
- wood decay, which could lead to a loss of lumber strength,
or
- the exposure of other materials that are moisture-sensitive
and susceptible to decay to high moisture levels and decay fungi.
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.