Bundles of wire

[ivsenroute]

Is that foam ASTM E 84 rated or could there be other problems?

Thought this was interesting and photo was published by the copper industry showing a fire hazard due to bundling.

 

[BryanMD]

I doubt the EC put that stuff there. It was probably done by the insulation crew or the GC's clean up & prep guy's.

I don't think I've ever seen a resi crew that had firestop caulk either; have you?

 

[Jhaney]

that foam looks like the stuff you can get at any big box store and I didn't think that was fire rated

 

[iwire]

I am willing to bet in that application it does not have to be fire rated, that looks like draft stopping not fire stopping.

 

[augie47]

I am correct that under 334.80 in '08, the "caulked" hole would require derating of the conductors irrerspective of their being "bundled" beyond the hole, correct ?

 

[GrayHeadedMule]

Can't specify the section but isn't there an allowance for wires to be bundle together like that as lond as it's not more than 24 inches.

Don't know where this comes from. Just a memory of mine!


And yes it is draft stopping and it is also required by the energy codes

 

[ivsenroute]

I am willing to bet in that application it does not have to be fire rated, that looks like draft stopping not fire stopping.

You are correct. From what is visible, this is a flam spread/smoke density issue and not a fire-stopping problem. Chances are that the foam does carry the ASTM E-84 rating which is all that is required.

In our area, it is a mix for who does the foam and firestopping (where required) with situations where each contractor takes care of their own or the GC has the insulation crew do all smoke spread and firestopping.

The real issue here is the bundling and derating. This photo is directly from the copper industries website and they called this a fire hazard.

 

[GrayHeadedMule]

Are 310.15 B 2 and 334.80 contradicting each other?

310.15 B 2 is where the 24 inches was stuck in my mind.

 

[augie47]

I am correct that under 334.80 in '08, the "caulked" hole would require derating of the conductors irrerspective of their being "bundled" beyond the hole, correct ?

I question myslef, as I don't see any mention of "bundling" or "distance" in the revised wording to 334.80, in fact, they seem to specifically remove "distancve". As I read it, the caulking alone will now require derating where there are multiple romex cables. So you see it differently ?

 

[infinity]

Think of the draft stop as a 24" bundle. As far as Article 334 is concerned they are the same.

 

[Dennis Alwon]

Here is the article from NEC 2008

334.80 Ampacity.
Where more than two NM cables containing two or more current-carrying conductors are installed, without maintaining spacing between the cables, through the same opening in wood framing that is to be fire- or draft-stopped using thermal insulation, caulk, or sealing foam, the allowable ampacity of each conductor shall be adjusted in accordance with Table 310.15(B)(2)(a) and the provisions of 310.15(A)(2), Exception, shall not apply.