1/8-Inch Gaps

Are 1/8-inch gaps at penetrations in corridor walls still allowed?

No.  TJC has updated their position and the "unsealed spaces 1/8-inch wide or less around pipes, conduits, ducts, and wires above the ceiling" are no longer permitted in existing corridor partitions. 

Elements of Performance for LS.02.01.30

C 6. Existing corridor partitions are fire rated for 1⁄2 hour, are continuous from the floor slab to the floor or roof slab above, extend through any concealed spaces (such as those above suspended ceilings and interstitial spaces), are properly sealed, and are constructed to limit the transfer of smoke.

Note 1: Unsealed spaces 1⁄8-inch wide or less around pipes, conduits, ducts, and wires above the ceiling are permitted.

Note 2 1: In smoke compartments protected throughout with an approved supervised sprinkler system, corridor partitions are allowed to terminate at the ceiling if the ceiling is constructed to limit the passage of smoke. The passage of smoke can be limited by an exposed, suspended-grid acoustical tile ceiling. The following ceiling features also limit the passage of smoke: sprinkler piping and sprinklers that penetrate the ceiling; ducted heating, ventilating, and air-conditioning (HVAC) supply and return-air diffusers; speakers; and recessed lighting fixtures. (For full text and any exceptions, refer to NFPA 101-2000: 19.3.6.2.1 and 19.3.6.2.2)