The extension to our house is built to earthquake standards, so there are 10x10 posts and beams everywhere. We can't find a path to feed the 12AWG to the subpanel. If we go down, we just run into the same problem on the ground floor. Can't go up because it's a flat roof. Any ideas?

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    Are surface wiring methods unacceptable for some reason? Commented Oct 14, 2019 at 1:13

3 Answers 3


Also look into the Conduit wiring method. This allows you to put up to four circuits (or even more with a wire size bump) into a single hole/pipe, instead of only one or two cables.

This works because you are fitting individual wires into a pipe, instead of a sheathed cable containing multiple wires, so you don't have the bulk of the sheath, packing and grounds. All the circuits in a pipe can share a ground, and if the pipe is metal, it can be the ground.


This is worth confirming, but in my experiences, all makers of engineered lumber has install guides to direct where and how big holes can be made in their products. These are available on line at the manufacturers website. If I knew the brand and the material in question I could look it up, but....

  • Thanks. We will ask our contractor and look it up. He did mention that we can't drill holes through it, which might be code here in Oregon. Any ideas about chiseling a channel and cover with metal strip? Is that common practice in your experience? Otherwise, we will go with the decorative strip.
    – Catherine
    Commented Oct 13, 2019 at 23:14
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    A channel (notch) is much worse than a hole. Structural materials can accept a veritable swiss cheese of (non-edge) holes without losing any significant strength; it's SOP for airplane wings, for instance. Consult with the material manufacturer; they'll know. Commented Oct 14, 2019 at 0:23
  • In most, if not all jurisdictions, the engineer or written specs from the manufacturer is what the building inspectors go by. Because if glulam is the name on the material, that is the name Boise Cascade uses that is registered. That will give a starting place to look.
    – Jack
    Commented Oct 14, 2019 at 1:57

Put a Crown Molding, Decorative Strip or Cornice around the ceiling and run a cable behind that. Conversely, the baseboard(s) can be removed and any wiring can be run behind that, at the bottom of the wall(s).

  • It's all open right now, but the post runs floor to ceiling. There is then a beam across to the other side, with another post. They are determined that this thing not come down in an earthquake!
    – Catherine
    Commented Oct 14, 2019 at 1:43
  • @Iggy cheers for the edit - could have done your own!
    – Solar Mike
    Commented Oct 14, 2019 at 3:35
  • Nah, you were on the right track.
    – Iggy
    Commented Oct 14, 2019 at 9:19
  • We found a way through the post. If we hadn't been able to do that, I think we would have run the feed line halfway down the circuit. At that position, we could go down to the ceilling of the lower floor, then down the bay between two joists, then into the old part of the house. The glulams on the ground floor aren't so impenetrable.
    – Catherine
    Commented Oct 19, 2019 at 22:19

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