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Posted By: ThinkGood Fireblocks - drilling holes - 04/01/03 04:22 AM
A neighbor is having a "gut job" done on his house--now it is down to the bare wood.

The contractor is putting in fireblocks in between the existing studs (this is an old house, no fireblocks were used originally) before the electrician comes in to completely rewire the house, before the sheetrock goes up. (By fireblocks, I mean 2x4s that are cut to fit in horizontally between the studs.)

I got to thinking (yeah, I know, thinking can be dangerous)...if the electrician is possibly going to need to drill through fireblocks, doesn't that open a whole can of worms, in that that the fireblock is then compromised? Does the electrician need to seal around the cable to completely fill the hole, or does this apply only to commercial dwellings?

I can't imagine that the guy is going to have to seal every hole drilled vertically yet I find it ironic that an area with electric cable would have holes in the fireblock...
Posted By: Bill Addiss Re: Fireblocks - drilling holes - 04/01/03 04:35 AM
TG,

This Blocking is commonly used in the Interior walls. We call them "Cats" (Anyone know why?)

I've never heard of holes through them being an issue but am curious about the requirements for these. I did find something in the NYS Resi Code (which is a modified IRC) Electrical Section, but not sure what it means:

E3302.3 Penetration of firestops and draftstops. Penetrations through fire blocking and draftstopping shall be protected in an approved manner to maintain the integrity of the element penetrated.

Bill

[This message has been edited by Bill Addiss (edited 03-31-2003).]
Posted By: CTwireman Re: Fireblocks - drilling holes - 04/01/03 05:21 AM
Here in Connecticut we are required to fill these holes with fire stopping (retarding?) compound.
Posted By: nesparky Re: Fireblocks - drilling holes - 04/01/03 07:50 AM
see 300.21
A lot of places say if you drill it you seal it.
Posted By: lwinter31 Re: Fireblocks - drilling holes - 04/01/03 08:24 AM
This is really not a big issue here. 2 to 4 vertical pulls per room max to seal. The just of cable in walls is pulled horizontally in residential installs.

Bill ? - CATS=(Cuss At Them Suckers)?
Posted By: Redsy Re: Fireblocks - drilling holes - 04/01/03 12:08 PM
We are regularly required to "fire caulk" penetrations that separate 2 floors. The caulk can cost $10-15 per tube.
Posted By: ThinkGood Re: Fireblocks - drilling holes - 04/01/03 01:17 PM
Thanks for the quick response.

nesparky: 300.21 -- That's the one I remembered but couldn't find.

I've never noticed any kind of caulking, etc. in the photos here (and elsewhere) that show Romex through holes. (OK, many of the photos here are posted to show violations anyhow :eek [Linked Image] nor have I seen it in the few newly-built houses I have seen.

I did find the caulking online--one site had it for about $9 per tube.

Interestingly enough, I found some articles (via Google searches) that stated that fiberglass insulation, when the barrier material is covered, is better than wooden fireblocks.

lwinter31: Your explanation of "cats" sounds very plausible [Linked Image]

As usual, you folks gave great information.
Posted By: Electricmanscott Re: Fireblocks - drilling holes - 04/01/03 02:07 PM
Here in MA I beleive you are required to seal penetrations between floors. Not 100% sure though, general contratctors usually do this.
Posted By: pwood Re: Fireblocks - drilling holes - 04/01/03 06:51 PM
fireblocking required in walls at ten foot intervals.fireblocks required at soffits.fire blocks required at stair stringers.a dab of fire caulking at the penetrations is sufficient if the product is listed that way.if the fireblocks are not code required no protection is required.
Posted By: ken m Re: Fireblocks - drilling holes - 04/01/03 10:46 PM
here in s.c. the blocks are called perlins or perliners (sp) they are only required in interior walls that exceed 8' in height. the requirements are to use the mortar or caulk in the top and bottom plate not the perlin and of course that depends in which county the job is located. ken m
Posted By: electure Re: Fireblocks - drilling holes - 04/02/03 01:24 PM
Here in So CA, land of "sticks & stucco", these aren't considered to be fireblocks at all. The requirements for blocks are 3 from a corner, and 2 from an opening (door, window, etc). We're required to seal holes in exterior walls (for insulation reasons), but not interior, unless they're through the wall's top or bottom plate.
Since RX isn't rated for any firewall penetrations, I can't remember the issue of firecaulking around it ever coming up.
Posted By: nesparky Re: Fireblocks - drilling holes - 04/03/03 02:03 PM
A lot of times when we do a single family house, fire caulking is not enforced by the structural inspectors. When we do apartments it is always enforced. The electrical inspectors here do not look at fire caulking leaving it to the structural inspectors. This is because more than electricians make holes in framing.
Posted By: ThinkGood Re: Fireblocks - drilling holes - 04/03/03 06:04 PM
Well, so far, my neighbor was told "no fireblocking is needed at all" when he called to ask. The GC went in person and was told that it is needed, first floor only.

nesparky:
Quote
...more than electricians make holes in framing.

Yep. I believe (I may be wrong...) water pipes, especially heating/hot water pipes, need space around them to allow for expansion/contraction of the copper and to prevent noise from banging.
Posted By: Bjarney Re: Fireblocks - drilling holes - 04/03/03 10:56 PM
You might do a google search for “intumescent caulk”.
Posted By: ThinkGood Re: Fireblocks - drilling holes - 04/04/03 01:06 PM
Man, there you go with that intumescent vocabulary!
Posted By: LuminateME1 Re: Fireblocks - drilling holes - 04/05/03 12:52 AM
Fire caulk (from what I've learned) is only required in holes that have been drilled from one unit to the next unit. Example: If you have an apartment, where you have someone living above you,and holes are drilled between floors,then you would have to fire caulk those holes made between units. Note: if the the floors in the unit are in the same dewelling (meaning: the aparment has and upstairs, and down stairs), then you would only use foam.
Posted By: Mike Wescoatt Re: Fireblocks - drilling holes - 04/08/03 04:47 PM
Here in Nevada we have these in all new homes. When we bore a hole in them we are also required to seal them. We can use intumescent caulk, or fiberglass from fiberglass insulation jammed in the holes, or regular cualk on both sides.
Posted By: JerryF Re: Fireblocks - drilling holes - 04/08/03 09:35 PM
The International Building Code requires the holes in firestops to be sealed. It's usually done by the insulation compane.
Posted By: Bill Addiss Re: Fireblocks - drilling holes - 04/12/03 09:47 PM
I just came across the following while browsing the Michigan Rehab Code for Existing Buildings

Quote
109.3.4 Frame inspection. Framing inspections shall be made after the roof deck or sheathing, all framing, fire blocking and bracing are in place and pipes,
chimneys and vents to be concealed are complete and the rough electrical, plumbing, heating wires, pipes and ducts are approved.
Is this the procedure followed where you are?
I think that the Framing Inspection where I am is often done before any other Trades get in there. What is the norm?

Bill
Posted By: nesparky Re: Fireblocks - drilling holes - 04/13/03 11:37 AM
Around here the framing inspector will not show up untill the electrical HVAC and plumbing inspectors have signed off thier rough ins. If called they look on the plans to see the rough in stickers (the Gc is required to have approved plans on job site), if they are not there the framing inspector red tags job as not ready for inspection and walks away and charges the GC with a re inspection fee.
Posted By: iwire Re: Fireblocks - drilling holes - 04/13/03 12:12 PM
Bill,
Same thing here in MA the building inspector is last, I imagine to see what damage the trades have done to the structure and insulation as the building inspector verifies energy code compliance here.

As to who seals the holes, we try to negotiate that out of contracts (along with anything else that is not directly electrical) but often we end up doing the sealing.
Posted By: Bill Addiss Re: Fireblocks - drilling holes - 04/13/03 01:29 PM
The way that I've seen it happen is:

Framing Inspection (no Trades in yet)
Rough-in Electrical (maybe Plumbing too)
Insulation Inspection (after Insulation is in)
Finals (any order)

Bill
Posted By: pwood Re: Fireblocks - drilling holes - 04/18/03 08:17 PM
around here all inspectors are required to be combination inspectors.we do framing,plumbing,electrical,and mechanical in the same day.i think most building departments prefer the multi-purpose inspectors and we will become the norm.
Posted By: Steve T Re: Fireblocks - drilling holes - 04/19/03 12:44 AM
Fire-caulking is required for any spaces that are required to maintain a certain rating such as between floor. This means around any space around any type of penetration. Large spaces are allowed to use Rocksul ( I think thats the spelling) which is basically a fiberglass insulation. Properly rated caulk as listed by UL as suitable for the purpose doesn't breakdown when it gets hot and stays pliable so expansion and contraction of penetrations do not create additional gaps.

The proper caulk around here is about 15 bucks a tube.
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