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sealing drilled penetrations(residential)

Posted By: mpelectric

sealing drilled penetrations(residential) - 08/03/05 03:27 PM

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.
Posted By: foestauf

Re: sealing drilled penetrations(residential) - 08/03/05 03:38 PM

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.
Posted By: Tiger

Re: sealing drilled penetrations(residential) - 08/03/05 06:03 PM

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.

Dave
Posted By: foestauf

Re: sealing drilled penetrations(residential) - 08/03/05 11:22 PM

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.
Posted By: HLCbuild

Re: sealing drilled penetrations(residential) - 08/04/05 12:03 AM

mpelectric,
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.

Harold
Posted By: Jps1006

Re: sealing drilled penetrations(residential) - 08/04/05 12:15 AM

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.
Posted By: gfretwell

Re: sealing drilled penetrations(residential) - 08/04/05 04:37 AM

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.
Posted By: harold endean

Re: sealing drilled penetrations(residential) - 08/04/05 12:21 PM

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.
Posted By: DougW

Re: sealing drilled penetrations(residential) - 08/04/05 01:55 PM

Quote

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.
Posted By: Paul O'Connell

Re: sealing drilled penetrations(residential) - 08/06/05 04:17 PM

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.
Posted By: dlhoule

Re: sealing drilled penetrations(residential) - 08/09/05 02:07 PM

Different areas have different practices.

Doug & jps 1006: Do you have someone drill holes for you too?
Posted By: eprice

Re: sealing drilled penetrations(residential) - 08/09/05 03:54 PM

Some here are getting this confused with fire rated wall construction. The requirement to seal holes drilled in plates and studs is not limited to fire rated walls. Section R602.8 in the IRC requires fire blocking in various locations. The UBC and IBC have similar requirements. Among other places, the IRC requires fire blocking:

1. In concealed spaces of stud walls and partitions, including furred spaces and parallel rows of studs or staggered studs: as follows:
1.1 Vertically at the ceiling and floor levels.
1.2 Horizontally at invtervals not exceeding 10 feet

In a typical wall, the studs and the top and bottom plates also serve as the required fire blocking. Section R602.8.1.2 Requires that the integrity of all fireblocks shall be maintained. If holes drilled in top or bottom plates would allow fire to pass through, then the integrity of the fire blocking has been compromised. If holes drilled in studs would let fire spread for more than 10 feet horizonally, the same would be true.

[This message has been edited by eprice (edited 08-09-2005).]
Posted By: George Little

Re: sealing drilled penetrations(residential) - 08/09/05 04:26 PM

eprice- I agree with you on your statement with respects to the IRC. We have the MRC here in Michigan and it is basically the IRC with the Michigan twist on it. The issue we have run into is that we still have inspectors who insist that the contractors use fire rated material (fire caulk) when it is rather obvious that since it is not a fire rated wall or assembly that a fire rated material is not necessary. There are several cases in the IRC/MRC that address using fiberglass insulation as a fire blocking material. To lazy to give code references but I can and will if someone is interested.
Posted By: eprice

Re: sealing drilled penetrations(residential) - 08/09/05 04:39 PM

George,

Yes, I agree. And I have spoken with a representative of ICC about this. No official interpretation, so take it for what it is worth, but the individual I spoke with concurred that fire caulk is not required when the only issue involved is maintaining the integrity of fire blocking. He stated that expanding foam would not be acceptable because it is too insubstantial, and I would add, burns too well. But a good silicone caulk, or as you say, fiberglass insulation would work. I have seen some expanding foam that is fire resistant. I think this would be acceptable as well. How do you feel about that?
Posted By: George Little

Re: sealing drilled penetrations(residential) - 08/11/05 01:13 PM

I don't see a problem with fiberglass insulation- properly installed so it stops air flow and don't fall out. I'm from the days when we used to use asbestos cement to "firestop" and when the drywall guys were nailing drywall you could count on the dried out cement falling out so you'd end up with no blocking what so ever. Using fire caulk in a combustible structure is like killing a fly with a 12 gauge shotgun.
Posted By: gfretwell

Re: sealing drilled penetrations(residential) - 08/11/05 04:03 PM

We had a seminar about fire rated assemblies and one of the main points they made was simply squirting fire caulk in a hole does not make this a firewall. It needs to be part of an engineered fire rated assembly or you are just wasting caulk.
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