During our work we often have to make holes through walls, top plates, fire blocks, etc.

Now, we all "know" about the red caulk, and fire-rated walls. But what about the family home? Do we seal where the romex gos through the fire-blocking? How? Just any old caulk? A little expanding foam?

More to the point- where do we find exactly what 'the code' requires?

Certainly this is up to the AHJ but the interpretation I have see in SW Fla is this is not a fire rated assembly in R3 unless you are talking about a garage with living quarters over it.
Foam is the usual fire stop material. I have heard a lot of discussion about foam. Some of it is nasty in a fire. (smoke and dripping fire)
They may reevaluate it soon.

In my area the Insulation Contractor is responsable for sealing all holes created by the subs work.
so...we do not worry about it.
This applies to resi work only.

In my area, we need to firestop "large" holes. These are up to the descretion of the inspector, but we usually stuff rockwool around pipes and ducts. The holes from wires are ignored. If I'm trying to cut down on the draft created by them, I'll use latex caulk or the white foam that stops expanding once it is in the hole.

I always "knew" that holes could be patched by using the same methods and materials as were used in the original construction. For example, you could patch a hole in sheetrock with joint compound- it wasn't necessary to use the red caulk, or any other special product.

The challenge was in documenting what I "knew." Well, I found it....

NEMA, in co-operation with UL, conducted a study that documented this, and other, practices.

"Annular Space Protection of Openings Created by Penetrations of Tubular Steel Conduit- A Review of UL Special Services Investigation File NC546 Project 90NK11659"

This summary, as well as the full report, are available from NEMA.

"Anyone can have an opinion- but DATA is what makes one opinion stand out from the pack!"

reno,

could you be more specific? I tried searching NEMA's website no no avail.

In reference to the residential fire caulking, the IRC is a bit more specific:
Fireblocking is required "at ceiling and floor level, with an approved material to resist the passage of flame and products of combustion."
We all know that "approved" means acceptable to the inspector, and what is acceptable to all inspectors is a listed product used in accordance with that listing. Or, in other words, red caulking.

when wiring any structures whether its a wood house or a high rise in northern virginia, maryland and washington d.c. we must firestop -any -penetrations that go from one floor to the next or through any fire rated walls with rockwool or fire caulk. even small ones such as holes for romex,mc,emt,rg6 and cat5. the electrical inspector enforces this and will fail you for it. as well as any fire mashall or building inspector

Well...we just got rejected on a concealment inspection on this very issue. Our inspector wants the red fire-rated caulk used to fill holes around the electric wires and other small holes. I was told they just started enforcing this in residential construction in my area.

You need to read the UBC and not just the NEC.

In fire rated walls boxes must be mounted to the studs, (no "cut-in" boxes unless maybe you can cut them in next to and mount them to the stud instead of useing "hold-it" clips) Boxes in opposite wall faces must be at least 24" apart center to center. (to insure that they aren't in the same stud space.)

The UBC also specifies the sealing methods around penetrations in fire walls. You won't find an article in the NEC to qoute or to dispute with the inspectors. If you want to be informed you will also have to be familiar with the UBC codes.

No I'm not trying to be a smart aleck....just stateing a fact. It takes more than NEC knowledge to perform and comply as a proffessional nowadays.

Ausador, the wording used by the UBC for mounting boxes in rated walls is from the UL orange books, so it can be found there or on the UL web site with out the need to own UBC literature.

Roger

Florida is revisiting this as I said upthread. They have changed the wording of the code for plate penetrations fron "draftstopping" to 'fireblocking" which will eliminate foam in wood construction.
This is still not the same as "firestopping".
I can see that this will be another year of trying to decide what 67 counties and 500 cities will consider appropriate. They seem to be as interested in smoke as they are fire. I suppose red caulk will always work but it is probably more than you need.

You've got to admit, the whole idea of "fire rated" cauking in wood frame construction is pretty silly... especially in view of all the other combustible materials like insulation, carpeting, drapes, furniture, etc.

Using fire stopping on wood frame construction is kind of like putting a steering wheel lock on Rolls Royce and parking in the South Bronx... a lot of good it'll do.

If we're truly serious about fire safety and protection, we'd stop using wood framing and construction altoghether. If I were to build a new home for myself from scratch, I'd go steel and concrete.

At minimum, the newer fire resistant paint and wood treatments should be applied with all new construction. By the way, anybody have any opinions on these treatments?

Joe

That is why they say "fire blocking". It just blocks the rapid spread of fire products (smoke) and delays the actual spread of the fire so you have time to get out. If the wall cavity is really fairly well sealed the fire might choke itself out before it ever really gets loose. It is not really that easy to light the side of a 2x4. If you have foam in there the foam itself may be the biggest accelerant for the fire. It certainly will not help the smoke problem.

As I understand it, fire behaves in ways that sometimes seem to be the opposite of "what common sense would tell you."

In actual fire tests, wood framed walls perform identically as walls with light steel framing. Indeed, contrary to popular expectations, the wood members don't burn, so much as slowly char away.

This all changes if there is active airflow across the wood. That's why draft stops and fire blocks are so critical. Again, testing showed the old practice of blocking every 4 ft was no more effective than blocking every 8 ft, so the requirement was dropped. We now 'block' only at each floor level.

It is correct to note that the vast amount of fuel is in the contents, rather than the building itself.

It is also quite correct that we need to know more than just the electrical code!

Are any jurisdictions still on the UBC?
California recently made the switch to the International Code. I thought we were the last to do so.
(The need to know Codes other than the NEC is the reason that this forum area is here)

[quote=JJM]At minimum, the newer fire resistant paint and wood treatments should be applied with all new construction. By the way, anybody have any opinions on these treatments?[quote/]

Out here at Sequoyah Nuclear, the carpenters apply a chemical to all wood used inside the plant. The chemical makes the wood fire resistant. Not sure for how long, but it turns the wood blue. It also weakens the wood also... not sure on the specifics though. Any one else heard of this?

Luke, I am not familiar with the exact product / method you describe, but....

It sounds like a bromate (bromine salt) solution is applied. I don't see how it would 'weaken' the wood, but it might make the surface softer.

Any treatment applied to wood, to make it "fire resistant", has only been evaluated to reduce the surface flammability of the wood. That is, the ability of a flame to catch on the face of the wood, then spread along the surface. There is absolutely no reason to think that the wood will, ultimately, burn any differently than "normal" wood.

AFAIK, all 'fire' and 'rot' treatments applied to wood are based upon some sort of salt (though not necessarily table salt!). Keep this in mind, especially in moist areas; those same salts will corrode metal just as well.

Reno you bring up a good point about corrosion. I assume you guys know if you are shooting fasteners or attaching galvanized boxes to the new PT lumber it will rust off your nails, screws and straps. This stuff is tough on anything steel, galvanized or not. The green fasteners are OK but stainless is better. They originally said double hot dipped galvanized will work but I am hearing, "not so much", from my lumber supplier.