Intent 1:
To limit the probability of:
- if shingles were too short, insufficient overlap of
wood shingles at the desired exposure, which could lead to an insufficient
number of shingle plies over the roof surface, which could lead to
coinciding defects,
- if shingles were too narrow, splitting, exposed joints
or defects in underlying courses at joints between shingles or shakes,
or
- if shingles were too wide, shrinkage and cracking.
This is to limit the probability of
precipitation or meltwater ingress, 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.