8.15.1.2.6 would normally not require and additional fire stopping on our part for typical construction. For a typical 12in TJI spaced 16in O.C. the required run would have to be over 120ft long before the 160ft^3 is exceeded. 8.15.1.2.8 is only requiring the insulation in the space BETWEEN the bottom of joist and the ceiling, not the entire space. Happens a lot with ACT ceiling installed 6in below the joists.
Your right on about 8.15.1.2.7 and the non-3000ft^2 area, unfortunately the GC's are never wanting to do this at their cost. Dewayne -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bobby Gillett Sent: Monday, January 28, 2013 2:05 PM To: [email protected] Subject: Concealed Space - compsite wood joists NFPA 13 - 2010: 8.15.1.2.6* <http://codesonline.nfpa.org/a/c.ref/ID00001327787/sec> Concealed spaces formed by ceilings attached to composite wood joist construction either directly or onto metal channels not exceeding 1 in. (25.4 mm) in depth, provided the joist channels are firestopped into volumes each not exceeding 160 ft3 (4.53 m3) using materials equivalent to the web construction and at least 3 1/2 in. (90 mm) of batt insulation is installed at the bottom of the joist channels when the ceiling is attached utilizing metal channels, shall not require sprinkler protection. 8.15.1.2.7 Concealed spaces entirely filled with noncombustible insulation shall not require sprinkler protection. 8.15.1.2.8 Concealed spaces within wood joist construction and composite wood joist construction having noncombustible insulation filling the space from the ceiling up to the bottom edge of the joist of the roof or floor deck, provided that in composite wood joist construction the joist channels are firestopped into volumes each not exceeding 160 ft3 (4.53 m3) to the full depth of the joist with material equivalent to the web construction, shall not require sprinkler protection. I have a concealed space formed by composite wood joists with ceiling attached directly to the bottom of the joist (no metal channels, so insulation is not a requirement). If I'm not mistaken, in order to consider it a space that doesn't require sprinkler protection I have to do the following: Per 8.15.1.2.6 - Have the joist channels firestopped into volumes not exceeding 160 ft³ OR Per 8.15.1.2.7 - Completely fill the space with noncombustible insulation OR Per 8.15.1.2.8 - Completely fill the space with noncombustible insulation AND have the joist channels firestopped into volumes not exceeding 160 ft³ (WHICH KICKS 8.15.1.2.7 OUT FOR COMPOSITE WOOD JOISTS ALTOGETHER) I guess what I am misunderstanding is if I have to firestop the joist channels into volumes not exceeding 160ft³ either way, why would we want to fill the joist space completely with noncombustible insulation? Only thing I could think of would be to keep from having to do a 3000ft² RA in the adjacent protected space. Any comments for my understanding would be appreciated. Bobby Gillett Sr. Project Manager Key Fire Protection, Inc. (731) 424-0130 office (731) 424-9285 fax (731) 267-4853 cell <http://www.keyfireprotection.com> www.keyfireprotection.com -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20130128/9cef5418/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
