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#88948 08/16/04 07:37 AM
Joined: Apr 2002
Posts: 178
What is required to meet code requirements for draft fire stop.Just finished rough in and city inspector insist on red fire stop calking compound.This where wire comes through top plate to boxes.I`ve seen some guys use insulation but we use a calk thats cheaper that the red but is fire retardant?I`m looking for a empty to see.What do you guys use and could this be a local deal..Thanks

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#88949 08/16/04 09:58 AM
Joined: Apr 2002
Posts: 7,333
Likes: 7
Presenting an 'empty' (or a full) tube of what you used to the inspector should be satisfactory IF what he requires (RED) is the same as what you used.

If the stuff you used is 'better' by spec, that what he requires, that should be acceptable also.

Fire stopping, and energy code regulations are becoming something all sparkies have to comply with, as more stringent enforcement, and revised requirements are 'surfacing'.


#88950 08/16/04 06:17 PM
Joined: Jun 2003
Posts: 681
A few years ago, the fire stop material that was available was red. Today there are more manufacturers producing the product and there are different colors available.
What you need to look for is; UL 1479 and ASTM E814 on the tube. There are some products that have UL 136, and that is not a fire stop product.
If you have more interest, The UL General Information For Electrical Equipment (White Book)has some pretty good information on page 258 of the 2003 version (XHEZ).


Pierre Belarge
#88951 08/16/04 08:15 PM
Joined: Apr 2001
Posts: 449
The Indiana building code calls for draft stopping material to be used where holes have been made in the top plates of framing wood in 1 and 2 family dwellings. Some local inspectors insist on fire caulk. I have never understood the reasoning for fire caulk to be used to seal a hole in combustable materials. It is obvious why it should be used to seal around holes in concrete, brick, block or steel, but those holes require metallic raceways if they are for conductors. I wired a house a few years ago where the insulating contractor used silicone caulk to seal all the wires where they went through the top and bottom plates. The inspector insisted they all be re-caulked with fire stop. The GC agreed to comply but asked why. The inspector didn't have an answer. The GC said that if this house ever burned down for some reason we could always dig through the ashes, pick up a little red ball of putty and say "Thank God we had these!" The inspector didn't insist on fire caulk the next house, just draft stop.

#88952 08/17/04 09:38 AM
Joined: Dec 2003
Posts: 886
The GC said that if this house ever burned down for some reason we could always dig through the ashes, pick up a little red ball of putty and say "Thank God we had these!"

Well, not quite.

Fire stop caulking is made to expand around the cable and choke it off when exposed to a flame. Even though it is used in a hole drilled through combustable material, it offers a degree of protection since it can take a while for fire to penetrate a 2x4 and especially a double 2x4 plate. Without fire stopping the flame would immediately follow the cable up through the hole to the other side and spread.

Ordinary caulk or RTV will burn (actually it will contribute to the fire) and immediately deteriorate and offers no protection other than possibly preventing a draft or chimney effect in the bay.

In my view using a listed fire stop material is a small price to pay for the added safety.


#88953 08/18/04 03:03 PM
Joined: Aug 2003
Posts: 64
Fire fighters' lives have been lost because fires thought to be isolated to one part of a building have unexpectedly emerged somwhere else, or because roof or floor structure has been weakend to a greater than obvious extent, because fire has traveled unseen within concealed building spaces. The reason for fire blocking is not to stop a fire, but to hamper its progress and not allow it to spread rapidly within interconnected conceald spaces.

I have never understood the reasoning for fire caulk to be used to seal a hole in combustable materials

Fire blocking is more important in combustible construction than in non-combustible. That is because it is the combustible construction that allows a fire to grow and spread within the concealed spaces. Just how much will the holes drilled in plates or other fire blocks facilitate the spread of fire? Well, that depends on ths size of the hole. But remember, in a fire the jacket and insulation on the NM cable for instance will burn off rather quickly, so only the copper wires will be there to fill up the holes. The advantage of the right fire caulk is that it will expand to fill in the hole.

...we could always dig through the ashes, pick up a little red ball of putty and say "Thank God we had these!"

Well, the intent of the fire caulk wasn't to keep the house from burning down. Did the fire caulk slow the spread of fire so that someone got out that wouldn't have otherwise? Maybe we'll never know....

#88954 08/18/04 04:55 PM
Joined: Apr 2001
Posts: 449
I agree that draft stopping caulk should be used and hampers the spread of fire via stopping the flow of air to feed it. The state building code does not require fire caulk in wooden construction, it requires draft stopping material. In wooden construction of 1 & 2 family dwellings, wooden fireblocks are required horizontally between vertical studs where the stud bay exceeds 9'. This fire block is for the same purpose, to hinder any chimney effect. That's why balloon framing was outlawed. I did not mean to imply that draft stopping material was a waste of time, just that fire stop in wood is over-kill, in my opinion. Drafting via ceiling fixture boxes and recessed lights is a much bigger concern, in my opinion, but who seals those(other than me)? Think about it. If a fire originates within a room of a single story home the receptacles and plastic boxes melt first before the sheetrock is penetrated. Draft stop at the top plate prevents a draft from fueling a fire in a stud bay. A fire starts in an attic and the draft stop in the top plate does it's job but what about the 20 recessed lights and dozens of ceiling boxes? Combustion air is drawn rapidly through these openings right into the cellulose insulation creating a forge effect. I've seen hot spots in the attic after fires where the owner thought every ceiling light must have started the fire at once. I seal around ceiling boxes after sheetrock and before insulation and only use air lock, double insulated recessed light housings. I use fire caulk when I penetrate a wall or ceiling and it is needed to maintain the over all fire rating of the wall or ceiling. My first post was not meant to denigrate safe practices.

#88955 08/18/04 06:50 PM
Joined: May 2002
Posts: 1,716
Reel-Break, are the walls rated? If not it might be hard to use a fire caulk properly.

Fire caulks, to be recognized as such, must be used in a tested assembly.

Go to the page below to search for an assembly. sion=versionless&parent_id=1073995580&sequence=1

click on view listings.

If this is not a rated wall with a designation, any draft stop such as mineral wool, fiberglass, non-flammable caulk etc...
is just as effective.

Ask the inspector to specify an assembly recognized by a NRTL so that you can use the product correctly. [Linked Image]


[This message has been edited by Roger (edited 08-18-2004).]

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