Intent 1:
To limit the probability of water ponding on roof
surfaces for extended periods, which could lead to:
- water penetrating roofing membranes,
- accelerated weathering of roofing materials, or
- the roof's structural design loads being exceeded, which
could lead to excessive deflection and further ponding.
This is to limit the probability of
damage or premature failure of roofing components, which could lead
to:
- 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
- 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.
Intent 2:
To expand the application of Sentence 9.26.3.1.(1) to allow lower slopes where drainage is provided.