Well I don't know how you get 30 minutes if only rocked on one side per: 11.2.3.3.3 To utilize the room design method, all rooms shall be enclosed with walls having a fire-resistance rating equal to the water supply duration indicated in Table 11.2.3.1.2.
And in #2 - 2,260 still isn't enough unless you meet the same rating issue wherever an additional 275 sq.ft. might be. I have used room design in these cases a couple times particularly where the water supply was an issue. Imagine no three phase power and no water. Cutting a small attic in half saves the day with a single phase pump and small tank. Chris Cahill, PE* Senior Fire Protection Engineer, Aviation & Facilities Group Burns & McDonnell 8201 Norman Center Drive Bloomington, MN 55437 Phone: 952.656.3652 Fax: 952.229.2923 [email protected] www.burnsmcd.com Proud to be one of FORTUNE's 100 Best Companies to Work For *Registered in: MN -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Gregory Lindholm Sent: Friday, August 31, 2012 1:41 PM To: SprinklerFORUM Subject: RE: Attic Remote Area Yes, I was thinking about using the room design method. In this instance, there would be not reasonable was to remove the sheet rock in example #1, and pretty tough to do anything in example #2. Is there any reason not to use the room design method here? Greg Lindholm > From: [email protected] > To: [email protected] > Subject: Re: Attic Remote Area > Date: Fri, 31 Aug 2012 11:26:16 -0700 > > concur, we ignore even rated walls unless using room design method. > > There is new guidance on how to address small subsystems (such as dry- > pipe on loading docks or preaction in computer room) in the 2013 > edition of NFPA 13. This use to be a particularly tricky issue when > applying logic for an answer when the sub-system like a loading dock > uses spray sprinklers and the adjacent warehouse system uses ESFR. > See the June issue of Sprinkler Age for more information. > > Roland > > > > On Aug 31, 2012, at 10:57 AM, Cahill, Christopher wrote: > > > 1. Assuming they are the same system. Yes, where does it say you can > > reduce the area below 2,535? Getting the total area is almost a > > Cardinal rule. Only way out is room design method if it applies. > > But that entails being reasonably sure the required walls will > > remain after the legendary cable guy comes through. One reason the > > room design method is flawed, owners can take down walls without > > even thinking sprinklers (as long as they are 6' apart). I guarantee > > during inspection no one knows if it room design or not. > > I know we can't plan for the future. > > 2. Same answer. > > > > Chris Cahill, PE* > > -------------- next part -------------- An HTML attachment was > scrubbed... > URL: > <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/atta > chments/20120831/1ff2322f/attachment.html> > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120831/aaf31bdb/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
