According to the NC Building Code (sec 712.3.2 Membrane penetrations, ex.1) when using steel boxes there can be no more than 100s.i. of openings per 100s.f. of wall area. I have been told by several inspectors and an engineer that there can be only one opening per stud space without having to use a fire putty pad. I don't see any limitation in the Code regarding the number of openings in the same cavity. Am I missing something? FYI ... all boxes are opening on the same side of the wall.
openings in 1-hour fire wall
- Thread starter KHall
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bphgravity
Senior Member
- Location
- Florida
They probably are refering to boxes on opposite sides of the rated wall within 24" of each other. In this circumstance, protective methods such as putty pads would be required.
As stated by you, there is no restriction, other then area of openings, for boxes on the same side of the wall.
As stated by you, there is no restriction, other then area of openings, for boxes on the same side of the wall.
- Location
- Simi Valley, CA
I agree with Bryan
abe72487
Member
- Location
- Lewiston Idaho
Fire stopping
Fire stopping
Check with local Bldg Off. Also allied makes a fiberglass box that is rated for fire walls. I have also figured 100 square inches in 100 square feet. ceiling or wall. Also when panelboards are used in these wall we have allowed large sizes if they install two layers of s rock on wall one glue to back of panelboard.
Fire stopping
Check with local Bldg Off. Also allied makes a fiberglass box that is rated for fire walls. I have also figured 100 square inches in 100 square feet. ceiling or wall. Also when panelboards are used in these wall we have allowed large sizes if they install two layers of s rock on wall one glue to back of panelboard.
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