To limit the probability of an inadequate physical bond between the first and second coats of stucco, which could lead to stucco being of inadequate strength to resist gravity, lateral or impact loads, which could lead to delamination.
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).]