Fire Rated Walls

toastermaker

Should I be able to identify a fire resistive wall (during rough in) just by looking at the framing?

Should it be indicated on the blueprints? If so how?

I believe I got caught with my pants down today. Darnit.

Also, are there special or certain boxes I could use to overcome the two foot rule? I have not found it in the code yet. Any pointers would be appreciated.

Thanks,

mdshunk

Nope, not really. The finish material is what makes the fire rated assembly in most cases. If you see mostly wood framing and a little steel stud framing (mostly on a commercial job), ask questions. Chances are that they're going for some special fire rating on the steel studded wall (like an egress path on a high occupancy building). You can pretty much figure every wall on a commercial job will be a fire wall, with the only differences being exactly how many layers are going on. I can remember a job with two layers of 1" gypsum in the stairwells. I never found any boxes with that long of an hour rating, so everything was piped on the surface in those stairwells.

Yes. All different ways. Often it's just a circle or an octagon with a number in it, which will correspond with a print note. The note will say something like "Class 1 Assembly" or "5/8 Type X Gypsum" or somthing along those lines. Sometimes it will be right on the floor plan with an arrow pointing to the wall. Certain walls are typically always fire walls, like attached garage walls and ceilings and party walls in townhomes and condos.

Sorry to learn that. Try some suspenders, perhaps.

Yeah, you can use a "putty pad" (such as made by 3M) over your box to overcome that rule if you absolutely have to. Also, Allied has a few boxes now that are rated for such a use (up to two in the same stud cavity). They are the only manufacturer that I know of that have boxes listed for such duty. If you use them, be sure you have the manufacturer's and UL specs on them handy for the inspector, because I'm sure they'll throw a fit. Here's the documents you'll need:
http://www.alliedmoulded.com/Fire%20...d%207-2-04.pdf

Teetorbilt

Like md says 'on the blueprints'. 5/8" is another giveaway. Knowing your codes would be another.

__________________
You can't solve you're problems with the same level of thinking that created the problems.

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Peladu

If it's commercial then double 5/8's is another give away.

They sell Fire Caulking, dont sweat it.

JustaFramer

A job I was on a few years ago all the boxes needed the putty pad and mud rings.

mdshunk

Which does what for the required 24" seperation between boxes on oposing sides of a fire rated assembly? Absolutely nothing. Fire caulk is just for sealing around such penetrations, and will not permit you to install more of them.

Peladu

You know, you are correct. I blasted through the end of the post and flew right passed it. So no, the fire caulk would not work. I quess I need to start reading with my eyes open at all times.

jmic

Spare us the details, but hopefully there were no stray sheep on the job site.

__________________
___"Remember You Never Get A Second Chance To Make A First Impression"______________________
Joe

toastermaker

Thanks everyone,

The only thing I have found in the NEC so far is a FPN that says fire resistive constructions are systems and I need to go by the manufacturers instructions.

Does the NEC address this more specifically? In particular, placement of outlets for fire resistive construction. If so what article(s).

Should I study code requirements for other trades to learn when fire resistive installation of wiring is required or is there a guide geared more specifically towards electrical work someone can recommend?

Unfortunatley I dont think suspenders would help me. Like Teetor says, I think my salvation (if I ever get there) will be in knowing my stuff.

No stray sheep on this job.


Thanks again,

mdshunk

Nope, the NEC has purposely steered clear of this matter. There is a little information (not code) in Annex E of the NEC with regard to the fire resistance ratings (in hours) of various construction types.

This is covered mostly in the IBC, IFC and in your own state's fire and panic codes. It might be interesting to note that the IRC does not require fire rated sheetrock on garage walls, even thought most people do use it. The IRC only requires 5/8" type X on garage ceilings if there's a room above.

JustaFramer

http://www2.iccsafe.org/states/Seattle/index.htm



These are for Seattle however the sections that the state of WA doesn't recognize are clearly labeled. The IFC and the IBC are both linked from that page.

JustaFramer

That is weird to me. Under the UBC 97 attached garages had to have 5/8 type x. Also on the bottom side of stair's 1/2 inch is allowed now. Rediculious degrading egress like that with inferior product.