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Joined: Aug 2005
Posts: 1
Junior Member
I failed an inspection because the inspector said we did not seal all penetrations we drilled through 2 x 4 studs. We are in the habit of filling the holes penetrating the top plate with foam and have never had any problems. Now on our last rough in inspection it was failed because we did not foam the holes going horizontaly through the walls. Does any one need to do this also our does any one know th code that says I have to do this.

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Joined: Aug 2005
Posts: 49
Thats a building issue. Maybe it's a local municipality code.
But yeah we only foam holes that transfer between airconditioned space and non-airconditioned space.

Joined: May 2005
Posts: 706
Where required by the AHJ in this area, I've only sealed vertical penetrations, not horizontal. I use fire-rated caulk and leave an empty tube on the project at eye level so the inspector can see what I used. I hope you're not talking about expandable insulation foam, which I don't think is fire rated. I've heard of inspectors making guys dig out silicone and install the proper product.


Joined: Aug 2005
Posts: 49
No expanding foam is not fire rated. Fire retardent but not fire rated.
Don't need to fire stop verticle holes.
Only need to fire caulk where you penetrate a firewall. Even if knocking out holes for boxes you have to firecaulk entire way around the box heh. My only complaint about multi-family is dealing with firewalls.
Thankfull the unit that I'm on atm has nothing that goes through firewall:-) It's the other guys units that have to penetrate hehe.

Joined: Dec 2004
Posts: 209
I'm a general contractor and I've had to do this in 2 jurisdictions. They were both local codes. One was every hole in every stud. The other town said caulk the holes shut every 8 feet so the wall was made up of 8ft x 8ft areas. They were looking for "draft-stopping" which is different from fire-stopping. In most residential single family homes you can use caulk, rockwool, or other similar products. When you get into a fire-rated classification, the products change.


Joined: Jan 2004
Posts: 615
As an EC, we have never had to do anything to our holes. That is the job of the insulator or GC. But then it was just the top and and bottom plate. Except once when they wanted every hole caulked with fire caulk at the begining of a townhome project. Turns out there was a lack of understanding on someone's part, several hundred dollars of caulk later.......they really only needed the top & bottom.

Joined: Jul 2004
Posts: 9,935
Likes: 34
This draft stopping with spray foam is always interesting when you get a fire inspector arguing with an environmentally minded building inspector.

Take some out in the yard and light it with your lighter ... but be ready to drop it and get away. Hold your breath. The flame spread and toxic smoke problems far outweigh any small saving in energy you might achieve over rock wool or fiberglass IMHO. I have seen homes with a dozen empty cans laying around between the electricians, plumbers and window/door framers. That's a lot of extra nasty smoke in a fire.

Greg Fretwell
Joined: Feb 2002
Posts: 2,233
Here in NJ I believe it is required to seal up the openings. It is to prevent the spread of fire and also for energy conservation. It gets inspected by the building inspector in my towns.

Joined: Jun 2003
Posts: 1,143

Originally posted by Jps1006:
As an EC, we have never had to do anything to our holes. That is the job of the insulator or GC. But then it was just the top and and bottom plate.

+1 for this. Never had to plug horizontal holes, unless they penetrated a fire rated wall (most of our resi work, that's the furnace room only), and then the insulators did it.

Joined: Jul 2005
Posts: 56
What the code calls for is fire rated walls, ceilings and floors. It is also required when you run through cold air spaces. In apartments the fire rated walls would be those walls seperating units. In single family dwellings the only rated walls I know of would be those walls seperating the dwelling from the garage. In our area then it would be top and bottom plate, air handling spaces, and the garage dwelling seperation wall.

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