I need to upgrade a floor/ceiling assembly to comply with a 1 hour fire separation rule imposed by the City of Oakland as a requirement for condo conversion. My existing ceiling/floor is standard 1/2″ sheetrock hung from resilient channels on 2×10 joists topped with 2×4 or 2×6 T&G subfloor. I’ve been told by a city employee (verbally, not in writing) that I can do so by simply adding a layer of standard 1/2″ sheetrock to the ceiling and screwing it into the channels (not into the joists, which preserves the sound separation qualities). I’ve determined that rocking/taping/texturing/painting the entire ceiling will be expensive, so I’d like to explore what I can do from the floor side – the entire floor will be recovered anyway, so I don’t care about ripping up and replacing the floor coverings (currently vinyl and carpet, to be replaced with tile, vinyl and carpet). Do you have any idea what material I can add to the floor to get a 1 hour rating? Or will the 1/2″ sheetrock give me an absolute limit of less than one hour? (because the sheetrock and the framing will burn through in less than 1 hour, so it doesn’t matter what is on top because the floor will collapse once the framing is gone). Also, just in case I want to consult with an expert, who would I call to ask about this? My architect doesn’t know anything about fire separation assemblies…
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First your codes should be able to clearly identify what is required. Also the City should be able to give you a written direction/opinion.
For what it's worth, I'd say doubling up the ceiling is going to be your only way out.
These guys may be able to help you.
http://www.fcia.org
Regards
Mark
Quittintime
Edited 5/27/2003 4:00:12 AM ET by MARKCADIOLI
My architect doesn't know anything about fire separation assemblies...
Wow, this is their business. Anyway, the addition of the 1/2" from below is without question the cheapest way out and also gives you the protection where you need it most and that is on the bottom of the system. Fires tend to burn up.
carpenter in transition
You will need to add the sheet rock from below. The fire seperation is to protect the floor joists. You can have a fire proof floor, but it won't do you any good if there's nothing to hold it up.
I am no expert in this area.
But here is what you are dealing with. The code requires a 1 hour fire rating between the floors.
Now fire rate aseemblies consists of mock walls or ceilings that are built and tested in a lab until "failure". Failure is what what is defined in the specs.
Now there are possible 100's of different ways to solve your problem. Two that I can think of would the "fire resistant" paint and dense pack the bays will cels.
Both will probably increase the fire protection "somewhat", and maybe by a LOT. But unless you actually build some test units and have a lab test them you won't have 1 hr fire RATED assembly.
The only option that I can see is if you can find an engineering company that specialists in fire ratings. They may know of some assemblies that have been tested or they might know of ways that they can show the additional time need by doing calcualtion.