Mark and Geoff, I agree that this in no way chalks up to the equivalent of a fire rated wall. (I am still under the impression that the only window sprinklers and the associated glass construction requirements are the only assembly out there that would be equivalent. It's been awhile since I have to deal with this.) But the mention of the smoke partition and the addition of "without Obstruction" makes me think in a different direction.
The "without obstruction" means to me.....don't put a duct or soffit between the required closely spaced sprinklers and the glass. That is just my interpretation only. It is a prescribed alternative to a rated wall. Without wanting to stray from what Greg originally ask asked, there is code basis for the request made of him from the design professional. The code is saying you can do this. I can't speak to the thought process behind allowing the alternative or what it will achieve. Maybe the glass is such a common feature that the authors thought it warranted an alternative, but didn't want to require the more expensive glass and window sprinkler configuration. I can't follow what may be implied, but I understand the concerns raised. Just out of curiosity, does anyone know if this is still permitted in the newer additions of the IBC? Best Regards, Ken Holsopple -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Mark A. Sornsin, P.E. Sent: Thursday, September 03, 2015 9:15 AM To: [email protected] Subject: RE: Atrium I agree with Geoff. The problem remains the total wetting of the glass. This cannot be achieved with the horizontal mullions in place. Moreover, can "entire surface of the glass" be wetted using standard sprinklers in a water curtain arrangement as opposed to listed window sprinklers? Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection Engineer | Fargo, ND | direct: 701.552.9905 | mobile: 701.371.5759 | http://www.kfiengineers.com -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Ken Holsopple Sent: Wednesday, September 02, 2015 11:24 AM To: [email protected] Subject: RE: Atrium Roland, I don't disagree but..... If Section 404.6 (see below) of the IBC prescribes the closely spaced sprinklers and the architect choses that instead of the other options listed to protect the atrium, then is it that big of a jump to apply Sections 8.15.4 and 11.3.3 out of NFPA 13? (2007 edition.) I only ask because the commentary in the 2007 handbook seems to allude that the requirement to provide the curtains is driven by the building code(s) and the NFPA 13 gives the how to. 404.6 Enclosure of atriums. Atrium spaces shall be separated from adjacent spaces by a I-hour fire barrier constructed in accordance with Section 707 or a horizontal assembly constructed in accordance with Section 712, or both. Exceptions: 1. A glass wall forming a smoke partition where automatic sprinklers are spaced 6 feet (1829 mm) or less along both sides of the separation wall, or on the room side only if there is not a walkway on the atrium side, and between 4 inches and 12 inches (102 mm and 305 mm) away from the glass and designed so that the entire surface of the glass is wet upon activation of the sprinkler system without obstruction. The glass shall be installed in a gasketed frame so that the framing system deflects without breaking (loading) the glass before the sprinkler system operates. 2. A glass-block wall assembly in accordance with Section 2110 and having a 3/4-hour fire protection rating. 3. The adjacent spaces of any three floors of the atrium shall not be required to be separated from the atrium where such spaces are accounted for in the design of the smoke control system. Funny how the IBC doesn't mention how many sprinklers are required to be calculated. Is a calc even necessary or is it implied that you go to NFPA 13 for that? Best Regards, Ken Holsopple _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
