yea...this came about because there was a lot of focus on sloped ceilings and sidewalls and residential guides coming from manuf. This is when we started defining a horizontal ceiling because up to that point we said flat and smooth...just not horizontal. The manuf were excited because other designers (not me of course) were designing EC sprinklers in sloped ceilings of which they were not listed for. So, we came up with all these new definitions to clarify "flat and smooth AND horizontal". Coinciding with that was James' work on EC storage sprinklers and this is when he was testing his attic sprinklers and after that little exercise we realized just how much slope affected sensitivity so we put a "lid" on it (pardon the pun). The good question to ask now is where did we get the 2/12 pitch as the line for flat versus slope? Someone get me a beer and a few hours...
Steven Scandaliato, SET CFPS Principal 520.971.2322 > From: [email protected] > Subject: Re: Ceiling Slope Limit for Storage > Date: Wed, 5 Feb 2014 12:07:31 -0800 > To: [email protected] > > It first appeared in the 1999 ed of 13 (the edition that incorporated the > storage standards). I ever so vaguely remember it. I believe it was just > not realized prior to that and the starting point of the discussion was that > these fire (especially racks) are much more challenging with a very rapid > growth and all the criteria testing was with a flat ceiling. There was no > real data indicating the ability to control these challenging fires with a > sloped ceiling and we arrived at the current criteria. > > Roland > > > Roland Huggins, PE - VP Engineering > American Fire Sprinkler Assn. --- Fire Sprinklers Saves Lives > Dallas, TX > http://www.firesprinkler.org > > > > > > On Feb 4, 2014, at 3:36 PM, Gregg Fontes <[email protected]> wrote: > > > Could someone verify that I am correct in thinking that the 2:12 slope > > ceiling limit for storage above 12'-0 was first stated in the 1999 Edition > > of NFPA 13 and was not in NFPA 231 or 231C? > > > > Thanks, > > Gregg Fontes > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
