Intent 1:
To limit the probability of the retention of water
that has penetrated roofing or that has condensed on the underside
of underlay, which could lead to long-term wetting of sheathing, which
could lead to deterioration, which could lead to further:
- condensation,
- precipitation or meltwater 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 relative humidity, temperatures
of interior spaces or water accumulation,
- the generation of pollutants from biological growth
or from materials that become unstable on wetting, or
- further deterioration, which could lead to compromised
integrity of roofs or assemblies protected by roofs.
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.