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
rain or meltwater penetrating directly to roof decking or sheathing,
which could lead to deterioration, which could lead to the structural
failure of roofs or assemblies protected by roofs, which could lead
to harm to persons.