Intent 1:
To limit the probability that performance, with
respect to strength, airtightness, resistance to liquid-water transfer
and water-vapour permeance, will fall significantly below expectations.
This is to limit the probability of:
- excessive air transfer from the exterior through the
assembly,
- precipitation or meltwater ingress through the second
plane of protection, and
- the excessive accumulation of moisture transferred from
the interior.
This is to limit the probability of the failure of required
environmental separation elements, which could lead to:
- compromised thermal performance of components intended
to provide resistance to heat transfer, which could lead to an inadequate
control of the temperature of interior spaces or relative humidity,
- the generation of pollutants from biological growth
or from materials that become unstable on wetting,
- the ingress of water into interior spaces, or
- deterioration, which could lead to compromised integrity
of exterior walls or elements protected by exterior walls.
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.