To limit the probability that fire in a vertical service space containing a dumbwaiter, or fire in a storey, will spread to another storey by means of the vertical service space, which could lead to damage to the building.
To limit the probability that fire will spread from a storey into a vertical service space containing a dumbwaiter, which could lead to damage to the building.
To supersede the fire separation requirements for vertical service spaces stated in Sentence 3.6.3.1.(1).