Intent 1:
To limit the probability of an inadequate vent area
for roofs, which could lead to:
- condensation,
- the accumulation of moisture, or
- the formation of ice dams.
This is to limit the probability of:
- the ingress of water, or
- compromised thermal performance of components intended
to provide resistance to heat transfer.
This is to limit the probability of:
- 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,
- deterioration, which could lead to compromised integrity
of ceilings acting as environmental separators, or
- water accumulation in interior spaces.
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 supersede the requirement stated in Sentence 9.19.1.2.(1), where the air pressure differential from eave
to ridge is limited or where the space below the sheathing is interrupted
by framing.