To limit the probability that performance will fall significantly below expectations with respect to substrate preparation, application of surface primer, preparation and application of rubberized asphalt, including the treatment of cracks and joints, and membrane flashing.
This is to limit the probability of the premature failure of roofing, which could lead to water 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.