Seeing as how it sounds like the AHJ is not following 13 there is no way for the forum to answer. Is it legal for the AHJ to specify this in the first place? If so you'd have to ask the AHJ.
Chris -----Original Message----- From: Daniel Adams <[email protected]> Sender: [email protected] Date: Thu, 18 Nov 2010 11:58:00 To: <[email protected]> Reply-To: [email protected] Subject: Room design method with non-sprinklered combustible concealed space (Sorry, I hit a wrong key and this got sent before I was finished) In a 4 story apartment building with 2 levels of parking below, the AHJ has specified a design density of .20 gpm /sq. ft. to be used throughout. The construction is of composite joists (TJI's) which are not completely filled with insulation. -If designed using residential heads, under Special Design Approaches, section 11.3.1 (in 2007 NFPA 13) the area would be 4 heads [and the .20 density would be used in lieu of .10 as specified in 11.3.1.2 (2)] - (this approach will result in a huge end head pressure). -If designed using either the area-density or room design method, 11.2.3.1.4 (3) specifies that the minimum area shall be 3000 sq. ft. Using quick response heads and with the ceiling less than 10 ft., the area could be reduced, but *11.2.3.2.7.2 *states "If the building has unsprinklered combustible concealed spaces, the rules of 11.2.3.1.4 shall be applied after all other modifications have been made". *(11.2.3.2.7 *is for *Multiple Adjustments*, so if only ONE adjustment is being made (for using quick response heads), would *11.2.3.2.7.2* still need to be applied ?) Thanks for any insight on this Daniel N. Adams Designer Interwest Fire Protection, Inc. 404 Ironwood Drive Salt Lake City, UT 84115 Phone: (801) 746-4040 Fax: (801) 746-4043 [email protected] _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
