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#154186 - 07/10/04 06:33 PM putty patches  
gunther  Offline
Joined: Sep 2003
Posts: 60
One of the jurisdictions we work in started requiring fireproof putty patches that wrap around the box to be installed in fire walls. They are only requiring them in electrical boxes, not phone or fire alarm. I am used to the requirement that they have to be wrapped if they are within 24 inches of another box (on the horizontal plane only, not vertical), but now they are saying all electrical boxes. They claim to have been requiring them all along, but we have working in that jurisdiction for around twenty years and have never been required to do it before. Another strange thing is that we had already passed the electrical inspection and it was the building inspector that required it. When we called the electrical inspector about it, all of a sudden he agreed with the building guy.
Is this something that all of a sudden the inspectors got together and decided to start requiring?

Building Codes & Related References

#154187 - 07/11/04 03:20 PM Re: putty patches  
Roger  Offline
Joined: May 2002
Posts: 1,716
Gunther, these guys are way off base.

The fire proofing of the wall is pretty much as you stated (and a little more depending on the circumstances) with in 24" of other openings.

The phone, data, or what have you would also need to be protected if they created a big enough break in the membrane.

If you can ask them what code they are enforcing with out making big headaches for yourself I would like to know what it is, then we could counter.


#154188 - 07/11/04 07:58 PM Re: putty patches  
earlydean  Offline
Joined: Dec 2003
Posts: 751
Griswold, CT, USA
These guys are not kosher. Building code allows metal electrical boxes of all kinds (telephone, FA, and power), up to 100 square inches per 100 square feet of wall. Any one box has to be no more than 16 square inches, and boxes on opposite sides have to be separated horizontally by 24 inches.The exception is for putty packs or boxing with sheetrock.

Plastic boxes have listings based on the manufacturer. I saw some advertised that allow back to back boxes.

To allow telephone off the hook (lol) but not power boxes is simply a misunderstanding of the codes.

As for the electrical inspector bowing to the building inspector; he works for the guy. Not too many folks will contradict their boss in public.

The UL listing details this, as does the IBC:

"711.3.2 Membrane penetrations.
Membrane penetrations shall comply with Section 711.3.1. Where walls and partitions are required to have a minimum 1-hour fire-resistance rating, recessed fixtures shall be installed such that the required fire resistance will not be reduced.
1. Steel electrical boxes that do not exceed 16 square inches (0.0103 m2) in area provided the total area of such openings does not exceed 100 square inches (0.0645 m2) for any 100 square feet (9.29 m2) of wall area. Outlet boxes on opposite sides of the wall shall be separated as follows:
1.1. By a horizontal distance of not less than 24 inches (610 mm);
1.2. By a horizontal distance of not less than the depth of the wall cavity where the wall cavity is filled with
cellulose loose-fill or mineral fiber insulation;
1.3. By solid fire-blocking in accordance with Section 716.2.1; or
1.4. By other listed materials and methods.
2. Membrane penetrations for listed electrical outlet boxes of any material are permitted provided such boxes have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing.
3. The annular space created by the penetration of a fire sprinkler provided it is covered by a metal escutcheon plate."



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