Is an astragal required for double-egress cross-corridor pairs in health care smoke barriers?
According to the International Building Code (IBC), one of the requirements for these doors is:
The doors shall have head and jamb stops, and astragals or rabbets at meeting edges.
That’s where my “yes” came from. There is even an image in the IBC Commentary to illustrate what rabbets and astragals are. –>
Since most health care facilities are required to comply with NFPA 101 – Life Safety Code, often in addition to the IBC, I checked the LSC to find the same requirement. To my surprise, the section addressing smoke barrier doors in health care states:
Rabbets, bevels, or astragals shall be required at the meeting edges of pairs of doors.
Annex A clarifies that split astragals (2 pieces of meeting stile gasketing) are also considered astragals.
WAIT – rabbets, bevels OR astragals? I spend most of my time in the IBC so I hadn’t noticed this difference in the 101 requirements before. I’m so conditioned to provide an astragal for this application (rabbets aren’t very common these days), that I asked NFPA staff for their take on it to make sure I wasn’t missing something. I sent a link to an old post showing parallel bevels on double-egress pairs, and asked if this type of bevel would be compliant with NFPA 101.
The staff member confirmed that the parallel bevels are permitted, and a smoke seal is not required for smoke barrier doors, but the gap between the doors needs to be minimized to restrict the spread of smoke through the opening.
Most of these doors in new or recently-constructed facilities will be installed with astragals, because of the IBC requirement. But unless the Centers for Medicare and Medicaid Services (CMS) has a special requirement that I have not seen (this is not typical), the doors would not require astragals in order to comply with NFPA 101. This could be very important during the inspection of an existing health care facility.
If you have had experience with this – especially related to a Joint Commission inspection – please share your insight in the reply box!
Image: IBC Commentary