# Washer boxes in 1-hr wall between apartments



## Pcinspector1 (Apr 15, 2020)

Have you ever come across a plastic washer box in a 1-hr rated wall?

And have you ever seen a plastic washer box in the same cavity for the other apartment?

Looking for the code that prevents this?


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## cda (Apr 15, 2020)

Apply the electrical box rule?


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## steveray (Apr 15, 2020)

I believe they make rated ones....

https://www.amazon.com/Oatey-38470SP-Fire-Rated-Washing-Connections/dp/B00KHZAUN0


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## cda (Apr 15, 2020)

Trying to figure out which edition this is out of

IBC 711.3.2:

_1. Steel boxes that do not exceed 16 square inches (4” x 4”) may be installed provided the total area of openings does not exceed 100 square inches for any 100 square feet of wall area. _

_2. Boxes on opposite sides of a wall shall be separated as follows: _

_a. By a horizontal distance of not less than 24”. _

_b. By a horizontal distance not less than the depth of the wall cavity where the wall cavity is filled with cellulose loose-fill or mineral fiber insulation. (Not standard fiberglass insulation) _

_c. By solid fire-blocking complying with section 716.2.1. (Not practical for back to back boxes) _

_d. By other listed materials and methods. (This would include fire stop pads inside boxes or outside that covered all 5 exposed sides) _

_3. Listed box assemblies that have been tested for use in fire rated assemblies can be used in accordance with their listing and instructions._


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## cda (Apr 15, 2020)

See if 714.3.2 of 2015 IBC helps you


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## classicT (Apr 15, 2020)

Why not just get a rated box like.... https://www.siouxchief.com/docs/def...x-washing-machine-box-spec-sheet.pdf?sfvrsn=4


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## Pcinspector1 (Apr 15, 2020)

The plumber is going to install rated boxes, but I requested they should not be in the same cavity, he was looking for a way around the distance requirement. The building had plastic boxes back to back

Thanks for the information


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## cda (Apr 15, 2020)

You did not say remodel,,,

Did they take all the Sheetrock down?? 

Or what was kind of the scope of work?


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## classicT (Apr 15, 2020)

Pcinspector1 said:


> The plumber is going to install rated boxes, but I requested they should not be in the same cavity, he was looking for a way around the distance requirement. The building had plastic boxes back to back
> 
> Thanks for the information


Gotcha....that will be determined by the specific listing of the box being installed. Most will not permit back to back installation


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## Pcinspector1 (Apr 15, 2020)

cda said:


> You did not say remodel,,,
> 
> Did they take all the Sheetrock down??
> 
> Or what was kind of the scope of work?



Burn job, everything removed, going back with new.


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## cda (Apr 15, 2020)

_By other listed materials and methods. (This would include fire stop pads inside boxes or outside that covered all 5 exposed sides) _


Puddy them??

https://kineticsnoise.com/arch/images/isobacker.jpg


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## mtlogcabin (Apr 16, 2020)

You could drywall around them like in the old days


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## Yikes (Apr 16, 2020)

Pcinspector1 said:


> The plumber is going to install rated boxes, but I requested they should not be in the same cavity, he was looking for a way around the distance requirement. The building had plastic boxes back to back
> 
> Thanks for the information



Ty J's link to souixchief shows their rated intumescent boxes installed side by side against a metal stud that has openings in the stud, and a double stud assembly, effectively one large cavity.  It would be easiest for the contractor to purchase these fire-rated boxes.


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## Pcinspector1 (Apr 16, 2020)

mtlogcabin said:


> You could drywall around them like in the old days



We talked about 2x above as a block but with the piping below the box makes it difficult to block with the plumbing in the cavity..


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## ICE (Apr 16, 2020)

mtlogcabin said:


> You could drywall around them like in the old days


Like a thousand times before.


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## mark handler (Apr 17, 2020)

How do you get the STC rating?


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## Pcinspector1 (Apr 18, 2020)

mark handler said:


> How do you get the STC rating?



Double wall construction with a space for sound board between walls was the design before fire. I'll have to check the required STC rating, that was not on the rework plans. Still room for soundboard, nice catch Mark!


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## ICE (Apr 18, 2020)

mark handler said:


> How do you get the STC rating?



Ya gotta have everything?  New construction has two walls.  Old construction has zero STC rating.


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## jar546 (Apr 18, 2020)

I won't use the requirements for electrical boxes in this case because these are not electrical boxes and therefore that section of the code does not apply.


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## cda (Apr 18, 2020)

jar546 said:


> I won't use the requirements for electrical boxes in this case because these are not electrical boxes and therefore that section of the code does not apply.


 

it is membrane penetrations:::

Not just electrical 


*714.3.2 Membrane Penetrations*

Membrane penetrations shall comply with Section 714.3.1. Where walls or partitions are required to have a _fire-resistance rating_, recessed fixtures shall be installed such that the required fire-resistance will not be reduced. 
Exceptions:

Membrane penetrations of maximum 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that do not exceed 16 square inches (0.0 103 m2) in area, provided the aggregate area of the openings through the membrane does not exceed 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area. The _annular space _between the wall membrane and the box shall not exceed 1/8 inch (3.2 mm). Such boxes on opposite sides of the wall or partition shall be separated by one of the following:
By a horizontal distance of not less than 24 inches (610 mm) where the wall or partition is constructed with individual noncommunicating stud cavities;
By a horizontal distance of not less than the depth of the wall cavity where the wall cavity is filled with cellulose loosefill, rockwool or slag mineral wool insulation;
By solid fireblocking in accordance with Section 718.2.1;
By protecting both outlet boxes with _listed _putty pads; or
By other _listed _materials and methods.

Membrane penetrations by _listed _electrical boxes of any material, 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. The _annular space _between the wall membrane and the box shall not exceed 1/8 inch (3.2 mm) unless _listed_ otherwise. Such boxes on opposite sides of the wall or partition shall be separated by one of the following:
By the horizontal distance specified in the listing of the electrical boxes;
By solid fireblocking in accordance with Section 718.2.1;
By protecting both boxes with _listed_ putty pads; or
By other _listed_ materials and methods.

Membrane penetrations by electrical boxes of any size or type, that have been _listed_ as part of a wall opening protective material system for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing.
Membrane penetrations by boxes other than electrical boxes, provided such penetrating items and the _annular space_ between the wall membrane and the box, are protected by an _approved membrane penetration_ firestop system installed as tested in accordance with ASTM E814 or UL 1479, with a minimum positive pressure differential of 0.01 inch (2.49 Pa) of water, and shall have an F and T rating of not less than the required _fire-resistance rating_ of the wall penetrated and be installed in accordance with their listing.
The _annular space_ created by the penetration of an automatic sprinkler, provided it is covered by a metal escutcheon plate.
Membrane penetrations of maximum 2-hour _fire-resistance-rated_ walls and partitions by steel electrical boxes that exceed 16 square inches (0.0 103 m2) in area, or steel electrical boxes of any size having an aggregate area through the membrane exceeding 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area, provided such penetrating items are protected by listed putty pads or other listed materials and methods, and installed in accordance with the listing.


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## north star (Apr 19, 2020)

*# ~ #*

What is the applicable Code that is being used
to rebuild after the fire ?........IBC, ..IRC, ..IEBC
or something else ?

Can they use mineral wool to pack around the
fire rated Washer Boxes ?........That [ may ] add
to the fire rating and cover the STC.

At least one manufacturer seems to cover both
the fire rating and the STC..........Check out the
Link to Rockwool:

*https://www.rockwool.com/*

*# ~ #*


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## Pcinspector1 (Apr 20, 2020)

north star,


north star said:


> What is the applicable Code that is being used
> to rebuild after the fire ?.





north star said:


> Can they use mineral wool to pack around the
> fire rated Washer Boxes ?



IBC, group R-2

Yes, rockwool is an option, I'm pretty sure there's an STC rated wall with mineral wool in the cavity, not just around the washer box but the whole wall between units.

Mineral wool would be different than what was there and could create an insurance question or two as to whats the minimum code requirement. If over the minimum, the insurance company may not foot the bill.


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## mark handler (Apr 21, 2020)

Pcinspector1 said:


> I'm pretty sure there's an STC rated wall with mineral wool in the cavity, not just around the washer box but the whole wall between units.


https://www.rockwool.com/siteassets...ofing-Solutions-Brochure.pdf?f=20180618130445


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