Fire rated ceiling?

[powerplay]

In a one level strip mall with wooden trusses and steel studs between suites, the walls are double 5/8" drywalled and not considered a firewall, but a fire separation? The ceiling has double 5/8" drywall also...just curious if anyone has thoughts or seen issues that arise from cutting in steel boxes in the ceiling attached to wooden supports to flush mount ceiling lighting(if that's allowed), and using non-metallic sheathed cable through steel stud with grommets, passing through into the new wooden wall firechaulked within the suite. I have pulled in armoured cable to add peace of mind, but am curious, as I have been informed that non-metallic sheathed cable may pass through the separation wall between suites, firechaulked into the wooden wall within the new suite.

On another note, in a three story duplex with sprinklers, I have been informed that the local building code will allow a single gang box in the separating common wall between suites. Are there any online references that anyone knows of? I have been on another site that has commercial building references, but have been waiting for almost 3 days for an response. Local authorities have different interpretations, and it would be nice to hear some opinions?.. thanks again!

 

[powerplay]

...I know, it's an Building Engineer's question, but I figure it's all relative?

 

[construct]

In a one level strip mall with wooden trusses and steel studs between suites, the walls are double 5/8" drywalled and not considered a firewall, but a fire separation? The ceiling has double 5/8" drywall also...just curious if anyone has thoughts or seen issues that arise from cutting in steel boxes in the ceiling attached to wooden supports to flush mount ceiling lighting(if that's allowed), and using non-metallic sheathed cable through steel stud with grommets, passing through into the new wooden wall firechaulked within the suite. I have pulled in armoured cable to add peace of mind, but am curious, as I have been informed that non-metallic sheathed cable may pass through the separation wall between suites, firechaulked into the wooden wall within the new suite.

On another note, in a three story duplex with sprinklers, I have been informed that the local building code will allow a single gang box in the separating common wall between suites. Are there any online references that anyone knows of? I have been on another site that has commercial building references, but have been waiting for almost 3 days for an response. Local authorities have different interpretations, and it would be nice to hear some opinions?.. thanks again!

If there is no floor above, I know of no requirement for the ceiling to have a fire rating. Whether a wall separating tenant spaces requires a rating is based on the use of the spaces. For instance a business use next to a business would not require a rated separation. A business use next to a storage use would require a rated separation.

On the second question, you are allowed to have some membrane penetrations and through penetrations in duplexes. Here is a website to view the 2006 International Residential Code. Section R317.3 covers rated penetrations. I don't know what Building Code your jurisdiction is under, but this might be a place to start.

http://publicecodes.citation.com/icod/irc

 

[roger]

Typically all boxes must be secured to a framing member in rated assemblies which rules out the use of standard cut in type boxes.

Roger

 

[powerplay]

I ended up simply screwing 2 by 6 to truss above, to whcich I am screwing an octagon box with an wire entering the back firechalked. Th ceiling has access due to an new cable pulled in for the panel in the suite, and after we rough wire the suite, it shall be sealed with drywall again. The rooftop is open across ceiliong s of other suites...I thought the drywall goes above the suites wall, thorugh the ceiling to the roof, but since it has been compromised, I am being extra cautious about maintaining a seal above the ceiling.

Thanks for the feedback!

 

[61333]

Go with the local authorities way of doing it and you will make the Canadian inspector happy.