# installing receptacles in fire rated wall??



## LTH306

i'm trying to get more info on what is acceptable when it comes to installing device boxes for switches or receptacles in walls that are fire rated..??...i've herd it should be surface mount, i've herd you cant cut holes in those walls, i know that if you do have to cut open those walls there's fire rated sealant....however i never found anything that puts it in black and white what is acceptable, it would be sweet if there was a device box designed for fire rated walls....can anyone help me out??


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## tkb

I know if you cut a box into the wall, it needs to be attached to a framing member.
It cannot be held in by just madison clips.
This is a UL standard for fire rated walls.


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## MDShunk

LTH306 said:


> i'm trying to get more info on what is acceptable when it comes to installing device boxes for switches or receptacles in walls that are fire rated..??...i've herd it should be surface mount, i've herd you cant cut holes in those walls, i know that if you do have to cut open those walls there's fire rated sealant....however i never found anything that puts it in black and white what is acceptable, it would be sweet if there was a device box designed for fire rated walls....can anyone help me out??


I think that's all covered pretty well in the UL orange book, but the two main things to remember for old work is that the box must be physically attached to the stud, and you can't have boxes in the same stud bay on two sides of that wall. There's a lot more options and products you can use in new work. 

You doing new work or old work?


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## TOOL_5150

MDShunk said:


> I think that's all covered pretty well in the UL orange book, but the two main things to remember for old work is that the box must be physically attached to the stud, and you can't have boxes in the same stud bay on two sides of that wall. There's a lot more options and products you can use in new work.


Learn something new every day :whistling2: Oops!


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## Techy

going from memory... in a rated wall

boxes must be secured to framing

one box per stud bay

4"x4" max opening(this one i'm not positive on)


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## walkerj

16 square inch max opening size.

Cannot exceed 100 square inches in 100 square feet of wall.

No boxes back to back or within 24" horizontal unless a listed firestop assembly is used.

Boxes must be secured to framing members.

Nothing in a wall adjacent to an egress stairwell that isn't directly related to the stairwell.

Plus much more:thumbsup:


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## B W E

In Cali, you have to put fire pads on the box. Its like a 1/8th inch thick pad thats about 6" square, made of some funky sticky red crap. It has to cover all the holes on the back of a 4S box. Made by 3M,,,http://solutions.3m.com/wps/portal/...PM102FLRECAB2K44_nid=77WRFFR483beQH6W2S54F8gl


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## LTH306

MDShunk said:


> I think that's all covered pretty well in the UL orange book, but the two main things to remember for old work is that the box must be physically attached to the stud, and you can't have boxes in the same stud bay on two sides of that wall. There's a lot more options and products you can use in new work.
> 
> You doing new work or old work?



new work, but base building is already done, so the drywall is up already on the wall that is fire rated, so everything has to be fished in.


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## B W E

LTH306 said:


> new work, but base building is already done, so the drywall is up already on the wall that is fire rated, so everything has to be fished in.


If it's a fire rated existing wall, you will have to cut it open to mount your box to the framing and then have it patched. At that point, put on the fire pad then have the wall closed up.


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## MDShunk

B W E said:


> If it's a fire rated existing wall, you will have to cut it open to mount your box to the framing and then have it patched. At that point, put on the fire pad then have the wall closed up.


That's about as untrue as can be. There are several compliant fire rated boxes that can be secured to the stud that don't require you to cut anything open.


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## B W E

MDShunk said:


> That's about as untrue as can be. There are several compliant fire rated boxes that can be secured to the stud that don't require you to cut anything open.



Such as??


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## MDShunk

B W E said:


> Such as??


http://www.arlcatalog.com/Fan_Specialty/ONE-BOX Non-Metallic Outlet Boxes.htm

available in non-metallic and metallic. Both 2-hr rated.


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## B W E

MDShunk said:


> http://www.arlcatalog.com/Fan_Specialty/ONE-BOX Non-Metallic Outlet Boxes.htm
> 
> available in non-metallic and metallic. Both 2-hr rated.


Touche.......
I need to consider more often that there are applications that exists outside of what I am specifically familiar with. Please forgive me for questioning you, Sire. What if he is using flex? Or M/C?


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## MDShunk

B W E said:


> Touche.......
> I need to consider more often that there are applications that exists outside of what I am specifically familiar with. Please forgive me for questioning you, Sire. What if he is using flex? Or M/C?


So... if you have more than one cable, and you feel the need to use a non-metallic box instead of a metallic box, use a duplex connector. I think that most drops in fire walls are going to be single cable drops anyhow.


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## Xjourneybenderx

LTH306 said:


> i'm trying to get more info on what is acceptable when it comes to installing device boxes for switches or receptacles in walls that are fire rated..??...i've herd it should be surface mount, i've herd you cant cut holes in those walls, i know that if you do have to cut open those walls there's fire rated sealant....however i never found anything that puts it in black and white what is acceptable, it would be sweet if there was a device box designed for fire rated walls....can anyone help me out??


Have u ever herd of a fire pad? U put it on the back of your box . So it seals the box from any air around it. It's like a big play dohh pad.


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## MDShunk

Xjourneybenderx said:


> Have u ever herd of a fire pad? U put it on the back of your box . So it seals the box from any air around it. It's like a big play dohh pad.


Unless you have stricter local rules, there are only a few instances where you're actually required to use a product like a putty pad.


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## user4818

I got to use the One Box recently. Yeah, I know, just a few years late on the draw. Anyway, it was pretty neat except I wish them made them a little sturdier. I think they are polycarbonate and the box flexes around a little more than I would like. I guess that is the nature of how they are by virtue of how they are fastened.


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## MDShunk

Peter D said:


> I got to use the One Box recently. Yeah, I know, just a few years late on the draw. Anyway, it was pretty neat except I wish them made them a little sturdier. I think they are polycarbonate and the box flexes around a little more than I would like. I guess that is the nature of how they are by virtue of how they are fastened.


You'll get better at it. If you install it, and it's hour-glassed, it's installation error. The SmartBox is very sturdy by comparison, but is only suitable for Romex.


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## user4818

MDShunk said:


> You'll get better at it. If you install it, and it's hour-glassed, it's installation error. The SmartBox is very sturdy by comparison, but is only suitable for Romex.


I'm not sure what I did wrong in that case. The hole was cut perfectly and it was tight to the stud. Maybe I overtightened the screws? It was a 1930's house so the stud was likely far from perfect.


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## MDShunk

Peter D said:


> I'm not sure what I did wrong in that case. The hole was cut perfectly and it was tight to the stud. Maybe I overtightened the screws? It was a 1930's house so the stud was likely far from perfect.


I'm sure it trimmed out well anyhow.


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## user4818

MDShunk said:


> I'm sure it trimmed out well anyhow.


It sure did. :thumbsup: The wall was nasty though. 3/8" sheetrock as a base layer, with wood paneling over that, with another layer of 3/8" blueboard and plaster over that.


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## Xjourneybenderx

MDShunk said:


> Unless you have stricter local rules, there are only a few instances where you're actually required to use a product like a putty pad.


I have had to use them in multifamily apartments. In the party walls where the two units meet.


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## wcord

Xjourneybenderx said:


> Have u ever herd of a fire pad? U put it on the back of your box . So it seals the box from any air around it. It's like a big play dohh pad.


STI firestop makes a pad that you can place inside the box
Just used some a job, they worked great. The putty pads require that you access them before the other side of the wall is covered.
powershield™ Electrical box inserts
Features & Benefits:
• Easy installation! Just peel and stick to inside of box.
• Can be installed before or after wall is closed.
• Non-conductive liner face.
• Easy retrofit installation.
• Low profile for minimum impact on box volume.
• Tested and proven acoustical properties.
• One step installation saves time and labor.
http://sti.fmpdata.net/ftp/brochures_catalogs/STI_Firestop_Products_EC.pdf


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## Rick567

So if I used caddy mounting brackets to mount a low voltage and line voltage it would be a violation because they are not mounted directly to a stud. Here we had to use the putty pads if there was two boxes in the same bay.


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## Roger

Rick567 said:


> So if I used caddy mounting brackets to mount a low voltage and line voltage it would be a violation because they are not mounted directly to a stud.


No, the caddy bracket would meet the requirement of being securely fastened to the stud, the UL assembly doesn't require the box be directly fastened to a stud only that it be secured to the studs 



> * WALL AND PARTITION ASSEMBLIES*
> 
> *Metallic Electrical Outlet Boxes*
> 
> _Listed single and double gang metallic outlet and switch boxes with metallic or nonmetallic cover plates may be used in bearing and nonbearing wood stud and steel stud walls with ratings not exceeding 2h. These walls shall have gypsum wallboard facings similar to those shown in Design Nos. U301,U411, and U425. The metallic outlet or switch boxes *shall be securely fastened to the studs* and the opening in the wallboard facing shall be cut so that the clearance between the box and the wallboard does not exceed *1/8* in. The surface area of individual metallic outlet or switch boxes shall not exceed 16 sq in. The aggregate surface area of the boxes shall not exceed 100 sq in per 100 sq ft of wall surface._


Roger


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## Rick567

Thank you for the clarification. I did a hotel with those. Also with using the putty pad, if there is a opening on both sides of the wall then we had to use them.


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## nitro71

Last time I dealt with firestop you could have as many boxes in one wall facing the same unit as you wanted. The issue was if you had opposing boxes within a certain distance(24" sounds familiar) then you had to use putty pads on those boxes that were opposing and within that distance.


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## Fibes

nitro71 said:


> Last time I dealt with firestop you could have as many boxes in one wall facing the same unit as you wanted.


Read the last sentence of the UL metallic box info three posts up.


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## Eclectic Electric

Peter D said:


> I got to use the One Box recently. Yeah, I know, just a few years late on the draw. Anyway, it was pretty neat except I wish them made them a little sturdier. I think they are polycarbonate and the box flexes around a little more than I would like. I guess that is the nature of how they are by virtue of how they are fastened.


I have to agree with you. I always figured this type of box was solid as could be since it attaches to the stud.

But in reality, the box flexes quite a bit, it's not solid at all. It actually needs "far side support".

Any typical old work plastic box that attaches to the wall with wings is MUCH more sturdy and solid, there is no movement at all. The One Box moves all over the place.

Now that it has been mentioned, I did have 1 or 2 "hour-glass" on me. Not sure what I did to make them do that, but that is a separate issue.


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## user4818

Eclectic Electric said:


> I have to agree with you. I always figured this type of box was solid as could be since it attaches to the stud.
> 
> But in reality, the box flexes quite a bit, it's not solid at all. It actually needs "far side support".
> 
> Any typical old work plastic box that attaches to the wall with wings is MUCH more sturdy and solid, there is no movement at all. The One Box moves all over the place.
> 
> Now that it has been mentioned, I did have 1 or 2 "hour-glass" on me. Not sure what I did to make them do that, but that is a separate issue.


The one I installed was for a GFCI on a kitchen countertop. I was hoping for something a bit more substantial particularly for an outlet that is going to get used so frequently. I ended up using an oversized nylon plate to sort of add strength to the mix.


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