Replies

1. Expert Member
   BILL WICHERS | Sep 10, 2022 10:06am | #1

   You have to use listed materials, so you can't just use any pipe. The two most common ways to do this in the US would be to either use EMT (thinwall metal conduit), or surface raceway such as Wiremold's V500/V700 product line. Using conduit will give you a more industrial look. You can paint either system to whatever color you want, but make sure you use a bonding primer on the conduit that will stick to the flash galvanized survace -- not all paint or primer will stick to that stuff reliably.

   Back in ye olde days, it was common to run wiring on the surface because structures were usually retrofits when areas were first electrified. There were all kinds of surface mounted raceways and devices back then, but very few options now. I do remember seeing pictures of an old wiring system like you describe, with tubing that was formed by hand that looked like copper tubing. I don't think that system is in existence anymore, at least in the US.

   Bill

1. 
   DC_Contrarian_ | Sep 10, 2022 11:35am | #3

   I'd say it's a little more subjective than that. Granted, where conduit is required, only listed conduit can be used. However, in residential construction conduit isn't required, Romex can be used pretty much anywhere so long as it is protected where it is subject to damage. That protection can be provided by pretty much any building material, drywall and plywood are commonly used. I'd say it's entirely a subjective question as to whether copper pipe is a building material that provides sufficient protection to Romex, and the answer to that question is the opinion of the inspector. I'd argue that copper pipe provides superior protection to drywall, nobody's going to drill into it blindly for example. The inspector may feel differently.

   Now, where you're going to run into trouble is attaching that wire to outlets and switches. You can't just run the copper pipe into junction boxes meant for conduit, that's using fittings for other than their listed purpose (and the diameter doesn't match). So you'd have to figure out some way to maintain protection of the wire while still using fittings as intended.

   That said, I'd look into painting EMT with copper paint if this is the look you want. Copper is quite expensive right now and is going to be a pain to work with. Or even painting PVC conduit. A Google search tells me that decorative copper conduit is not uncommon in Europe.

2. 
   Chris_in_NC | Sep 10, 2022 10:25am | #2

   I guess the first question is, are you looking to solve a particular problem that requires the use of something different than NM cable (Romex) and recessed boxes, or are just going for a specific aesthetic?

   It's fairly common to use surface mounted conduit and electrical boxes on block and cast concrete walls, for example in garages and basements. It's extremely common on commercial/industrial buildings, where precast walls and block interior walls aren't going to be furred and drywalled. My day job is in a building like that; all of the switches and outlets are surface mounted and connected with conduit, along with surface mounted rigid air piping for air tools. All of the conduit/boxes/piping are painted the wall color.

   I'm not sure if the NEC allows copper as a rigid metal conduit material, but I think nice expensive red brass is allowed if you're looking for an industrial or steampunk look with polished materials. Also nice expensive stainless.

   There are valid reasons of cost and ease-of-use that make NM cable and plastic/fiberglass recessed boxes the default method. The wall becomes the protection for the wire, and most everything can be done with a drill and a hammer. Cutting and bending conduit for all of the wire runs, and then pulling wire through all of that conduit, is a lot more labor and material cost, even with the cheapest conduit materials.

   If you are going for the surface mount aesthetic, there's nothing to say that you can't mix different methods, so (for example) the parts of the house where you want that aesthetic can use a surface mount solution, and the other parts of the house can be cheaper/easier in-wall wiring. Not any different from many basement houses, where the main house would be in-wall, and the basement walls would be conduit runs.

3. 
   deb1221 | Sep 10, 2022 02:34pm | #4

   My thought was may be in could be a way to save money as not needing to spend time cutting holes in drywall (or other material) and the look could be incorporated into the design of the house. We are considering alternatives to drywall such as savaged wood and metal or plywood for wall and ceiling materials. With those options running surface mounted electrical would make sense. Not looking to increase costs. The house I saw and a nice look with cooper against the plywood walls. Thank you all for your responses.

1. Expert Member
   BILL WICHERS | Sep 10, 2022 03:53pm | #5

   My guess is that the extra material and labor to use surface mounted raceway would probably cost more than the conventional way of running everything inside the walls. The reason is that conduit (and other materials) have gone up a lot in price lately, and the cost for the wire isn't really any different between the NM cable you'd run in the wall and the THHN wire you'd run in conduit or raceway. This means you'd have more material costs AND more labor to cut/bend/etc all the surface raceway.

   I think you'd have a cleaner appearance with recessed wiring too. A lot of old structures -- which includes many buildings in Europe -- we're wired on the surface out of necessity. Imagine for a moment that you live in an old stone house in Europe. It's going to be awfully hard to recess wiring into those cut stone walls, so running things on the surface ends up being the only practical option. Since they have more of those very old structures over there than we do here, it makes sense that they'd have more options for surface mounted wiring than we do. The difficulty is that you wouldn't be able to import and use their materials, since they use very different standards from what we use in North America (different voltages, different color codes, even different wire gauge measuring systems).

   Personally, I much prefer the clean appearance of recessed wiring. Way back when I was a cable installed (not cable TV, datacomm cable), I used to put much effort into fishing wires into walls to avoid needing to use wiremold because I thought it looked better.

   BTW, for everyone:

   RIGID conduit in the electrical world is a SPECIFIC MATERIAL, known as RMC (Rigid Metal Conduit). EMT, the more commonly used thinwall metal tube, is Electrical Metallic Tubing and IS NOT RIGID CONDUID, even though it's "rigid" in the sense that it isn't flexible. Those two types of conduit should not be confused, since they use different fittings and are different materials as listed in the code books. There is also IMC, Intermediate Metal Conduit, which is a little like RMC but without threaded ends. I almost never see IMC used.

   Note that you can't use brase pipe, either, since it's not listed for the purpose. Electrical conduit will all be listed by a testing lab (UL, CSA, etc.) for use as electrical conduit, and the code requires that the materials you use be listed for the purpose. That means you can't, for example, use galvanized water pipe for wiring, even though it looks the same as RMC and uses the same fittings (almost -- the threads are a slightly different taper, even though they will fit together).

   Bill

2. 
   Malcolm_Taylor | Sep 10, 2022 04:53pm | #6

   deb1221,

   It can look great, and really complement the architecture, but it will considerably more expensive. The tasks associated with running electrical service in walls - holes in framing and the wall surface, etc. are quick and inexpensive. Do it if you want the look, but expect to pay a large premium, whether you do it yourself or use a contractor.