Ask Me Help Desk - New wiring in plaster walls

Ok, I need any help I can get on this one. I am rewiring my living room of an old victorian house built around 1900. The exterior wall is brick and the interior wall is plaster. The plaster was placed directly on top of the brick (no lath or wood inbetween). Does anyone have any experience with this? If so, are there any wiring solutions for outlets that don't envolve me running exterior wire conduit and boxes? I looked at possibly buying 1/2" pvc wire conduit and carving out a channel for it in the plaster, but I would have to carve out a decent amount of brick too which would be a huge pain in the butt. If anyone has any information, please help me out!!

We run into this a lot. Ove the years we've tried the groove thing and in one case we even used 2x2s to do another wall in the room... but both were far too much work for what we got... so now we just use WireMold and paint it the same color as the walls.

I'm afraid there's no middle ground solution. Pick the method you dislike the least and go with it.

I would think you have 2 choices, either Wiremold (as Rick suggested) or use 1"x2"s and sheetrock.

Can you install electrical in the floor?

I lived in a duplex in a historic district, and one of the things they did was to use metal floor outlets that had covers when not in use. Just a thought.

Thou the WireMold system and the floor outlets are a simple inexpensive method, the result may not be what your looking for.

There is a way if you up to it:

Type AC Cable, the actual designation for the metal cable commonly called "BX", is allowed by code to be embedded into a plaster finish applied directly on brick.

As you already know, the plaster needs to be channeled out the entire path of the cable , the cable needs to be supported with cable straps every 4.5 feet at least, they make small one hole straps to support this cable, see picture I provided.

Attach each clip with a plastic anchor and screw.

Of course, at any box location the plaster and brick will need to be drilled and chisled out to accept the depth of the flush outlet box. Use metal masonry boxes for these.

At each box the brick needs to be channeled out for the cable connector and cables where they enter the box.

After the boxes are set into the brick, and the cable is installed in the channels and supported, the entire system can be covered and finished over with fresh plaster.

This is a ton of tedious work between channelling the plaster, chiselling out the brick at outlet box locations, laying the cable and strapping, and then spreading plaster, but the finished product far exceeds the surface mounted systems, if you willing to do all this work.

Quote:

Originally Posted by hockeybrian

Ok, I need any help I can get on this one. I am rewiring my living room of an old victorian house built around 1900. The exterior wall is brick and the interior wall is plaster. The plaster was placed directly on top of the brick (no lath or wood inbetween). Does anyone have any experience with this? If so, are there any wiring solutions for outlets that dont envolve me running exterior wire conduit and boxes? I looked at possibly buying 1/2" pvc wire conduit and carving out a channel for it in the plaster, but I would have to carve out a decent amount of brick too which would be a huge pain in the butt. If anyone has any information, please help me out!!!

So tkrussell, what would be the difference between channeling AC cable with plaster over it or WireMold with paint over it? I'm just wondering if it wouldn't be easier to place the WireMold into a carved out channel, place a bead of caulking on either side and paint the room. The reason I would like to use the WireMold option is to avoid having to replaster since I'm not the greatest at it. I don't know, I'm kind of in the same boat as hockeybrian but the house we're buying has plaster-lath and no brick.
Also, how hard is it to put a fish tape through a knockout in an existing outlet or switch or ceiling or etc. box and pull new wire into that box? Thanks a lot.

Since this is a plaster/lath wall, there must be a void in the wall cavity, so why not just fish the cables ?
Wiremold cannot be plastered over since the fittings have removable covers and would need to be accessible at all times.

Fishing a snake into a knockout can be frustrating, but can be done with patience, skill , and experience. Takes knowing how to bend and manipulate the snake. Be the snake.

Quote:

Originally Posted by tkrussell

Since this is a plaster/lath wall, there must be a void in the wall cavity, so why not just fish the cables ?
Wiremold cannot be plastered over since the fittings have removable covers and would need to be accessible at all times.

Fishing a snake into a knockout can be frustrating, but can be done with patience, skill , and experience. Takes knowing how to bend and manipulate the snake. Be the snake.

You are right that there should be a void in the wall but speaking with the homeowner prior to the homeowner were buying from who lived there for about 20yrs and had a truck come through the living room wall, he said the walls are filled w/ bricks and debris and god only knows what else presumably as insulation or just to avoid a dumpster fee (the house was built in about 1890). And I've heard that from other home owners around town here that the walls will either have fire blocking (balloon framing) or look like the county landfill with all the crap that is stuffed in them. And to clarify, I wasn't thinking of plastering over the wiremold but rather caulking along either side of it and paint the same color as the wall. Right now I'm contemplating running 1/2" PVC Sch. 40 conduit on the outside below one of the laps on the siding (surface mounted but try to blend it in as best as possible) and painting it the color of the siding. This would only give me exterior perimeter wiring but it seems like it may be an easier more cost effective option especially since we have future plans to reside the house and then the conduit would be concealed. Plus I would think interior partitions would be easier to add outlets too because you drill holes up from the basement or down from the attic. I hope I'm not talking out of my butt, sometimes I get too many ideas in my head and they become ungrounded. Thanks for the time and patience.
Scott

I have notched out the channel. It's only about 6 inches until I can get to the floor boards. Can I run uf cable through emt and then have it come out once I get behing the nail covers or does it have to be AC. Thanks!

No does not need to be AC cable, your plan to use UF sleeved through EMT as protection is fine.

Have you considered poping off the baseboard and running the BX and boxes behind it. I have used this method in a few places and it works well. Luckily the code here allows this.