Plugmold is usually mounted on the surface of a wall. Folks often object to it for cosmetic reasons.
Yet ... looking at some plugmold I have around the house, I note that it's not much thicker than the usual drywall. "Wiremold" brand appears to be 3/4" thick, while the store-brand stuff on the workbench looks to be 1-1/2" thick.
What if ... you let it into the wall, attaching it directly to the studs, and butted the drywall right to it?
Does anyone see a code issue with that?
Along those lines ... is anyone aware of a 'flanged' plugmold intended for flush installation?
Reno: Over the years I have seen (and installed) 'Plugmold' in a few jobs.
Mounted to the sheetrock, on the backsplash, at the bottom edge of the upper cabinets, before the finish (tile,etc.) backsplash installed. Almost flush. HO was happy, inspector said nothing, it was on GFI CBs.
Way back in time, Wiremold made components that you could build within the 1-1/2" raceway, receptacles, "Lumiline" lights, and switches; then cut the cover plate to fill in the spaces. I do not know if it is still around. No inspector had any issues with that either.
Ghost: You're right on regarding a wall that is fire rated. Within the codes here in NJ only the wall separating a garage from living space is a rated wall. The ceiling is also fire rated within the garage, if living space is above.
The few that I have installed over time were in non-rated walls.
Push comes to shove, there are ways to overcome the rated wall issue. I do not know how Chicago codes are though.
Here any wall with a panelboard in it has to have continuous drywall on the other side. Apparently any place that the drywall is not continuous is considered as allowing a fire to get to the studs directly instead of burning its way through the wallboard first. Studs have no fire rating; drywall adds 1-hour but that only applies on the side that it's mounted on.
I personally can't think of a place where you might need plugmold where appearance would be that important. Even if you manage to hide or camouflage the outlets you're going to see a lot of cords.
Ghost: The few I did were for an architect, and a kitchen designer, both were their private residences.
The designer did not want any cutouts in the backsplash whatsoever; some wildly expensive Italian tiles.
The architect, one from the wilder side, had a marble backsplash and the only penetrations were for his pot fill by the cooktop. His was field assembled with the 'Lumiline' lighting, receptacles and switches. A real backbreaker install.
Needless t say, my men, and myself do not make any cuts in any finish materials, so it was not my issue, just their preferences.
Ghost: If you mount a panel in a SFD garage wall that is an exterior wall with sheathing and some type of finish exterior siding, that is allowed, correct?
The interior walls of the garage are sheetrock, as the ceiling.
The walls common to the garage and the living space are 'fire rated' (1 hour) and require max. 100 sq inch of penetration, per 100 sq ft of wall. Openings on adjacent faces must be a min of 24" apart, or protected with compliant fire resistant components. (ie: Hilti Putti Pads)
BTW - I was told by one of the UL guys that the minimum 24" horizontal separation was a sneaky way of guaranteeing that the penetrations didn't occur in the same stud bay, even in places built with 24" o.c. spacing.
There's a lot of confusion regarding penetrations, confusion made worse by "code wonks" trying to 'improve' things.
Let me be plain here ... I was present during, and took part in, the basic ANSI full-scale fire testing done at a "major testing lab" that developed the data upon which the codes were written.
The purpose of the testing was to see what effect various penetrations had on known, tested, and proven wall assemblies. Penetrations evaluated included both 'through' penetrations (pipes) and partial penetrations (boxes).
From this data were derived the 'rules' regarding the use of putty pads, the placement of penetrations, etc.
Putting it simply ... the rating of a wall is directly dependent on the simple thickness of the drywall. Since walls are tested as complete assemblies, with temperatures monitored on the "safe" side, the thickness measured is the combination of the coverings on BOTH faces.
Let me state that differently: a wall with 1/2" drywall on both sides tests out the same as a wall with one side open and 1" of drywall on the other.
In that manner, it really does matter whether the panel is surface-mounted or set into the wall. The effectiveness of "boxing" the panel in drywall depends entirely on how well it is done, as well as how many cable / pipe penetrations there are of that "box."
In the testing, 4" boxes did not cause the wall to fail. 4-11 boxes did make the walls fail. Thus, is was proposed that 16 square inches of penetration be allowed in each stud bay.
FWIW, there was little difference seen whether boxes on opposite faces were 'back to back' or separated, or whether the cavity was stuffed with insulation.
It's the stud 'bay' that matters .... so, conceivably, if the studs were 12" apart you could have a penetration of one face every foot and the wall would still pass the fire test.
When it got into the hands of the code writers, they chose to word things so that a 4x4 box, regardless of the mud ring used, needed a putty pad ... and these had to be at least 24" apart, without regard to the stud spacing. Strictly speaking, these "safer" requirements are not supported by the test results.
Naturally, cutting a long slot, one bridging several stud bays, will affect the fire rating of a wall. With almost all household walls using 1/2" drywall on each face, plus the lack of 'rated' doors or windows, it's safe to say that we're not talking about a rated wall in the kitchen or dining room. It's not an issue.
It's pretty hard to install multiple receptacles close to each other and still have everything come out in a straight line. Nor will the tile guy thank you for it! Plus, you invariably have a (technical) code violation when the thick tile forces you to use long mounting screws on your devices.
Folks often say "I HATE plugmold!" I'm not sure where this comes from, though I can see how a plugmold / Wiremold strip can look bad after a few years' catching paint and grime. (This is especially true when the Wiremold has to zig and zag all over the place before it reaches the plugmold or box.
Yet ... what if you could avoid all that? What if you fed the plugmold directly from the box, and set it into the wall? There would be very little projection, and the long, straight line would be a joy to the tile guy.
The big question is: How do you connect the plugmold to the house wiring? Those connections have to be accessible, and the components really ought to be connected to each other. Where does the GFCI go?
The GFCI placement is an issue, as the breaker is (now) supposed to be AFCI.