I have a 1940's house with interior walls made with old-style true-to-measurement 2x4's turned sideways in the wall cavity resulting in a wall with only a 2-inch wide cavity.

The walls are not structural/L.B.

Is it acceptable to take modern 2x4's and screw them into the sides of these old studs to get a modern-width wall before I run new electrical conductors?

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  • Is the wall too flexible or something? Why not run your electrical on the face of the old 2x4s and then add strips of 2x2 split at the electrical interruptions?
    – popham
    Oct 8, 2023 at 21:19
  • So basically like strapping the existing boards horizontally? I think that would add difficulty in installing the drywall screws and junction boxes, and my local inspector wants to see wires run through drilled holes as opposed to being stapled. Oct 8, 2023 at 21:22
  • Run 2x2s vertically with the edge aligned with the old 2x4s. Instead of drilling holes for the cable, just cut away the chunks where your wires run. There's a requirement that wireing should be 1-1/4" from the wall framing edge to protect it from drywall screws, where the 2x2's 1-1/2" would work with 12 gauge romex, which is thinner than 1/4".
    – popham
    Oct 8, 2023 at 21:53
  • @popham you know what, that does make more sense. That gives more protection to the wire, more room to aim when trying to hit a stud through the drywall and results in the exact same wall width I'd get by my OP method. Oct 8, 2023 at 22:50
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    @ThreePhaseEel they're for receptacles, and I don't want protrusions. This is only a 5-foot long wall that I need to deal with, so I'm only talking about 5 or 6 boards to fix this. Oct 9, 2023 at 2:10

1 Answer 1


Yes. Should have a good reason to reduce floor area.

The only reason I can think of is needing the extra depth for electrical boxes.

  • That is literally the only reason. I found a box in the wall someone had hacked the back inch off of to make it fit, so when I took the wall apart I could see all of the wire tucking from the back side of the box. The rest of the room had external conduit and severely-degraded wall material that needed to come off. Oct 8, 2023 at 21:24
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    There are shallow boxes, that maybe some the experts might recommend, instead of the normal deeper boxes. They would be cheaper than adding new 2x4s for an extra inch and a half, for a few boxes.
    – crip659
    Oct 8, 2023 at 21:31
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    @crip659 the typical shallow box—at 8 cu in—has insufficient box fill volume for an outlet. They don't even have enough volume to splice two 14 ga NM cables.
    – Huesmann
    Oct 9, 2023 at 12:49

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