mckellarman

I have a client with an retail unit that would like to add a mezzanine above existing ceiling grid. The steel is in place and they would like to use TGI for joists. How would we fire rate this ? The only thing I can think of involves removing existing grid installing 5/8" type x and fire taping. Seems like alot of work for only another 500sq/ft of space though. Thoughts ??

tom m

Dont know what code you follow or what building type you have. Also dont know if there is one tenant or multiple ones. Will the mezzanine be a seating area? or a display projection in the same room? Different rules here. Look @ IBC 711.3 then 706.3.9. By that it says 2 hours. If the building has a sprinkler then by section 505.52 you need one.

rpellerin87

If you look in the NBC of Canada, Division B, section 3.1.3.1., it states that a type E (mercantile) major occupancy joining another type E occupancy needs a minimum 2 hour rating. So to satisfy this you would need two layers of type x drywall, unless the current occupancy has a sprinkler system, then below the mezzanine would also need a sprinkler system (not cheap, been burnt on that one before).

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R. Pellerin
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simplejack

A mezzanine is typically open like a Balcony right, I mean it's not a second floor. So worrying about the fire Rating is kind of like Insulating a LOW WALL, we would have to get more details on the layout to give a good assessment. One thing for certain though, if it hasn't been used for awhile, and your building has a sprinkler system, you'll be moving and adding some heads around.

You should have some drawings from the Architect (that's what they get the big bucks for) but if your just winging it on the owners say so...Get a courtesy walk through with the Inspector before you bid the job out.