by Bob Armbrister, on Jan 24, 2020 12:00:00 AM
Q: Our Emergency Operations team does regulatory rounding every 2 weeks in a different unit or clinic. Our department is responsible for Life Safety. Recently, we did some rounding in our Cancer Center which is an outpatient service in a business occupancy building that is attached to the hospital. The Cancer Center building is 3 stories high and the hospital is 6 stories. There is a large open lobby with a stair and elevator between the two buildings. The cancer center has a 30-minute smoke wall that runs through the middle of it per the life safety drawings. One of the questions on our rounding sheet is "Do all the smoke barrier walls go to the deck?". I discovered that there is a large gap in the smoke wall above a set of double doors. As a group we have discussed this and there are conflicting opinions. One opinion is the walls have to go to the deck regardless. The other opinion is they do not since we have a dropped ceiling grid which also acts as a smoke barrier. Is there a right answer?
A: Boy… You’ve got a lot going on there. First of all, when was this facility constructed? New construction smoke barriers have been required to be 1-hour rated for decades. You may have a problem calling these barriers 30-minute rated. Secondly, all smoke barriers (i.e. barriers that separate two or more smoke compartments) have to be continuous from outside wall to outside wall and from floor to deck above. Section 18.104.22.168 does allow for smoke barriers to stop at interstitial spaces, provided the underside of the interstitial space provides the same rating and smoke resistance as the smoke barrier. A suspended grid and tile ceiling does NOT meet that parameter.
What your fellow employees may be thinking about is a smoke partition… not a smoke barrier. A smoke partition is a non-rated wall that resists the passage of smoke and is found in corridor walls and non-rated hazardous rooms. Those smoke partitions are permitted to terminate at the ceiling provided the ceiling also resists the passage of smoke. While NFPA does recognize that a suspended grid and tile ceiling may resist the passage of smoke, the IBC does not.
From what you are describing… it appears to me that the smoke barrier must go to the deck. Write up an ILSM assessment and get that barrier scheduled for repair. Next, is there a fire-barrier of 1-hour construction meeting the requirements of 8.6.7 separating the cancer center from the atrium and another 1-hour barrier separating the hospital from the atrium? Finally, is there a 2-hour fire-rated barrier separating the cancer center business occupancy from the healthcare occupancy?