Intent 1:
To limit the probability of:
- excessive exposure of the shortest shingles, which could
lead to insufficient overlap, which could lead to an insufficient
number of shingle plies over the roof surface, which could lead to
coinciding defects, or
- excessive exposure, which could lead to excessive unsupported
length, which could lead to an increased vulnerability to displacement
due to wind.
This is to limit the probability of:
- water penetrating directly to roof decking or sheathing,
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.