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drywall over plaster and speaker wire.

In my 60yo house, I have a few basement walls that are plaster over lath (and several unfinished walls, which i plan to frame/drywall). the surface of the plaster is very rough, presumably done on purpose some time ago (any ideas why?), and slightly cracked.

Since i'm dry walling other walls, i figured i would just lay drywall over the plaster rather than learn the art of plaster repair. Any reason i shouldn't do this?

Slightly more odd question. I want to mount speakers and lay speaker wire across this wall. i know i will have to cut the plaster/lath for the speakers which is fine. for the speaker wire, any thoughts on just routing a shallow groove on the back of the drywall to run the wires? will this make the drywall too fragile? not sure if this is the equivalent of scoring the drywall and hence cause a disaster. now that i type this, it occurs to me that i could also route the plaster, and hence leave the drywall intact. would that work?

A. Spruce
Re: drywall over plaster and speaker wire.

Can you overlay plaster with drywall? Yes, this is done all the time. You can also tape and float the cracked plaster with drywall tape and compound, saving the expense/step/work of hanging drywall.

Can you surface run the speaker wire? Yes, but it's not recommended. What happens when you hang a picture, plasma tv, shelving, etc., and inadvertently hit the wire with a tool or fastener?

A better idea would be to either use a surface mounted wire mold or to notch the plaster and run the wire inside the wall. Even better would be to remove the plaster entirely, run the speaker wires and any other wires and plumbing while the wall is open, then install drywall. This will allow you to insulate if necessary and keep all the important things protected within the wall. You will likely have to apply shims to the studs to flush the drywall with the existing outlets, door, and window framing.

Re: drywall over plaster and speaker wire.

In Germany, electrical wires are commonly mounted to the cement building block walls and then plastered over with the finish coat of plaster. Building codes do mandate exactly how far off the floor and away from door and window openings the wires must be run. Since German construction is mostly non-combustible, such a system is also fire safe. Any subsequent tradesmen knows exactly where the electrical wires will be located. Since the standard voltage is 220volt, this is a good idea. 440volt is also commonly found in homes. The space heater in my apartment had 440volt current with a plug the size of my fist.

Accidents can happen, however. One of my friends was drilling a hole through an interior masonry wall and drilled into a 660volt machine current line. Fortunately he was not grounded, but it knocked him off his ladder!

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