Question about floor/ceiling penetrations in a high rise.

Blog Post created by on Oct 26, 2015

Can anyone out there tell me how a builder in San Francisco was able to construct 2-22 floor and one 6 floor high rise building having 3 foot by 1.5 foot cuts in every electrical room floor assembl=y for the conduits and not having to seal them at all?? It's like a  chimney!