To limit the probability of an inability to resist gravity and lateral loads, which could lead to the detachment of lath, which could lead to the cracking of stucco.
Where stucco is applied to masonry chimneys, this is to limit the probability of precipitation or meltwater ingress, which could lead to the premature failure of chimney liners, which could lead to the escape of heat or flames, which could lead to the ignition of combustible building components, which could lead to damage to the building. [See intent for Sentence 9.21.4.6.(1).]