To limit the probability that a fire in a space below a ceiling membrane that forms part of a required fire-resistance rating of the ceiling assembly will spread into the plenum space through openings in the ceiling membrane, which could lead to the premature failure of the assembly, which could lead to the further spread of fire to other parts of the building, which could lead to damage to the building.
To make Appendix D information a requirement with respect to the protection of openings through ceiling membranes.