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nonsymettrical 2 hr wall

Inspector 102

Silver Member
Joined
Oct 22, 2009
Messages
355
Location
N/E Indiana
Trying to determine what is available for a 2-hour occupancy separation wall. Existing wall is steel stud with 5/8" firecode on each side. I am looking at UL U453 as an option which will require removal from one side which is okay. Any other options available that someone can suggest. The goal is to not remove one side of an existing finished space.
 
I think U453 will work. The changed side will need resilient channels and then 2 layers of gyp board, and the other side can remain the existing 5/8" gyp.
 
JBI - There are methods with gyp on both sides, but the goal was to not disrupt the finished side that is already there. Currently not a fire wall but because of change in occupancy of the "unfinished" side, they want to go nonsymmetrical. UL 453 seems like the likely candidate for this application. They will be creating a 1250 sf space for A-3 occupancy and need the firewall. A lot of expense just for arcade games and pool tables. Occupant load comes in at 84 (1250sf/15=83.3) but at least they do not need to provide fire suppression to space. Thanks again.
 
Check to see if it works with non-separated occupancies. What is the allowable area for the A3 in your construction type? what is the area of the floorplate?
 
I am going to say fire wall because it will need to separate this assembly area from the "B" occupancy. The existing "B" occupancy was a bowling alley that was constructed in 1994 and now a restaurant was built out beside this bowling alley. The "A" occupancy has a fire suppression system because of occupant load, but the remaining building is not sprinklered. The fire wall would have to extend to the roof deck which is noncombustible meeting 706.6. I do not see where this could be a fire barrier, but if I am wrong, point it out to me. I am willing to learn.
 
Never crossed my mind on that one. I guess it will have to be a fire barrier. The design professional is really going to have to sharpen his pencil on this one. I am going to have to dig deep so I can inspect it properly as built out. thanks.
 
You need the wall to make it two buildings


From 2008 RGLA


One option to keep in mind is that if a single occupancy fire area exceeds the threshold for a fire sprinkler system, the fire area can be separated into two or more smaller fire areas to keep the size of each fire area below the threshold. To utilize this strategy, the code user needs to go to Table 706.3.9. This table establishes the minimum fire-resistance rating for fire barriers within single occupancy areas.





http://www.specsandcodes.com/articles/code_corner/The Code Corner No. 27 - Fire Areas.pdf
 
Do you need the sprinklers for height and area or just because of the A use?

[F] 903.2.1 Group A. An automatic sprinkler system shall be
provided throughout buildings and portions thereof used as
Group A occupancies as provided in this section. For Group
A-1, A-2, A-3 and A-4 occupancies, the automatic sprinkler
system shall be provided throughout the floor area where the
Group A-1, A-2, A-3 or A-4 occupancy is located, and in all
floors from the Group A occupancy to, and including, the
nearest level of exit discharge serving the Group A occupancy.
 
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