UL Fire Resistive Wall Assemblies

[GCtony]

mtlogcabin, That's a good lesson right there. This I will store somewhere in my memory bank.

Ya all are killing me, You teach me one thing and it leads me to come up with 10 more questions! Like I tell my kids..."Not a day goes by that you don't learn something"

Someone mentioned sec. 717; is the wall cavity in a wall assembly considered a concealed space?

Reading the prior posts got me thinking of a condition I will be running into. I have a 1-hour tenant seperation wall that we will need to have PVC pipe within the wall for a central vac system. The pipe will run above the ACT ceiling, penitrate the wall, turn down inside the wall and come out the wall near the floor. I understand the pennitrations will require fire caulk but my question is; is PVC allowed to pennitrate the wall and permitted to be within the wall. My thought is no, in case of a fire, the PVC could melt and leave a hole in the wall. However, I've seen similar conditions but it's for plumbing, CPVC water lines, vent and waste. A little help on where this is found in the IBC would be helpful. I'm looking at 712 but I think I need to be looking elsewhere.

 

[steveray]

Tony...just like a ul listed wall# design, there are penetration designs as well....they days of "we'll just fire caulk it" should be over....there needs to be enough intumescent material there to seal the hole when the pipe melts away....in many circumstances I think caulking can be used up to about 2" pipe if the amounts are correct....Anything larger than that might require a manufactured "collar" that affixes to the wall and will seal the opening it is designed for....

 

[GCtony]

Another question a little OT but I don't think is worth it's own thread. It's regarding 1017, corridors

I have a 6000 sq ft tenant space in your typ. strip center. A-3 use, type II construction, not sprinkled, architects calculations are showing 90 occupants. Imagine a space with rooms on the right of the space and rooms on the left with a corridor running down the center with an exit at the front and rear of the corridor. The distance between the two exists, length of the corridor is roughly 80 feet. Plan review is saying that the corridor will need to be rated per table 1018.1. It's black and white but I've never run into rated corridors within a small tenant space. I'm wondering if this corridor in this tenant is not technically a corridor and just a common path of travel. The architect did use the word "corridor" on the drawings. This plan reviewer is looking at exactly what is on the drawing and wont be doing the "oh, it's a mistake but I know what they mean, let me give them a call"

 

[GCtony]

Tony...just like a ul listed wall# design, there are penetration designs as well....they days of "we'll just fire caulk it" should be over....there needs to be enough intumescent material there to seal the hole when the pipe melts away....in many circumstances I think caulking can be used up to about 2" pipe if the amounts are correct....Anything larger than that might require a manufactured "collar" that affixes to the wall and will seal the opening it is designed for....

Thanks steve, Fire caulk or sleave seals will cover the actual pennitrations but does PVC pipe inside the rated wall affect the performance of the assembly, just like installing the wood blocking mentioned above? We've been installing PVC and wood blocking in rated walls forever. What I'm getting at; have we unknowingly been doing this wrong all these years and also being missed by our inspectors?

 

[steveray]

I know this is not really correct but.......

603.1.2 Piping.

The use of combustible piping materials shall be permitted when installed in accordance with the limitations of the International Mechanical Code and the International Plumbing Code.

I don't think it is an issue other than vertical exit enclosures which shall not be used for anything but egress (in a nutshell) no using those walls as a chase and nothing in them that does not serve the stairwell.....

 

[north star]

+ = >

GCTony,

The use of piping [ pvc & others ] is an approved material to

be installed inside of rated wall assemblies......The sealing

of the penetrations IS paramount though!......We typically

require the intumescent fire caulking around pvc piping

that penetrates or passes thru rated assemblies.



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