The easy and CONSERVATIVE answer is to say the entire foot print but lets look at what we are trying to accomplish and what is NOT said. Lets start with the question are we required to cover the intermediate landings (any of them)? No. We aren’t protecting the intermediate landing at the bottom. IT’s protection BENEATH it, IF there is open space for possible storage. So, wouldn’t that apply to our consideration regarding the top of the shaft? So teh standard does NOT tell us top protect intermediate landings. What is the objective of the protection at the top? It’s to cover the TOP landing in case someone does stick a bunch fo stuff there. Unfortunately, that's not stated in the standard so we have to revert to logic (which isn’t always accurate - lol). Oh yea, it is stated in the Handbook which USUALLY is helpful.
Under FAQ Why are sprinklers required in noncombustible stair shafts at the top of the shaft and under the first landing above the bottom of the shaft? The storage of materials in stairwells obstructs the egress route and is prohibited by NFPA 101. However, if there is an open space under the first landing or a large landing at the top of the stairs it is often an irresistible location for transient storage. As a result, 8.15.3.2.1 requires sprinklers at these locations. SO if we are concerned with the TOP landing (aka adjacent to the doors) why worry about placing a second sprinkler elsewhere? Since it is poorly worded in the standard, discuss this with the AHJ. NFPA caveat as a 13 committee member: just my opinion and not to be considered an official interpretation of NFPA or any of its’ technical committees. Roland Huggins, PE - Senior VP Engineering American Fire Sprinkler Assn. Dallas, TX http://www.firesprinkler.org <http://www.firesprinkler.org/> Fire Sprinklers Saves Lives > On Sep 21, 2018, at 6:02 AM, Ben Young <[email protected]> wrote: > > I'm curious to see how the rest of the people on the forum handle protection > at the top of the stair shaft, as we have an internal debate in our office. > > The 2007 edition of the NFPA 13 handbook has an exhibit, 8.29, which is on > page 334, and is involved with 8.15.3.2.1 in the 2007 edition. > > If you're not familiar with the picture, I'll see if I can get a scan, but > its basically a cross section of a stair tower, and has two circled letters > on it: B under the lowest intermediate landing, and A above the top main > floor landing. > > Basically this Exhibit and the explanatory handbook text after 8.15.3.2.1 > implies that the head at the top of a non-combustible stair shaft is only to > protect the top floor landing, and NOT the entire footprint of the stair > tower itself. > > So under this code, the interpretation was that you could protect a 24x10 > foot large stair tower with only two standard spray heads. > > Does anyone else feel this is appropriate? Or how do you feel about the > code/handbook change and the nuance behind this situation. > > I will start with the discussion by saying that I see the appeal of only > installing the one head over the top floor landing as installing another head > at the top over the intermediate landings can often be difficult to do off > ladders, especially if its a very tall stair tower. > > I also can also understand that from an AHJ perspective, 'sprinklers > installed at the top of the shaft' in the code language would be > conservatively read as the ENTIRE top. > > What are your thoughts? > > Thanks, > Ben Young > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
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