Putting TV cables inside a plasterboard wall cavity - Is my plan reasonable?

Question

I'm mounting my tv on the wall at the weekend and want all the cables hidden in the wall but easily accessible. I've found these backplates that I'm looking to use:

The plan is to cut out a section of plasterboard next to the wooden stud, attach a new stud section for the cables to fall down in to as the wall contains insulation material which would make it hard to run cables through, put one of these plates at the top and bottom, then put a new bit of plasterboard there, screw it on to the new stud and the existing one and plaster over it.

I've drawn up in AutoCAD before and after - legend:

• Green: Plasterboard
• Blue: Stud
• Red: TV
• Purple: VESA Mount
• Grey: Backboxes (I'll have to cut a section out of the bottom/top of the backbox to allow the cables through)

Before:

After:

The only difficulties I see are: - Screwing the new stud pieces in to place, half under the existing plasterboard. - There may be a noggin across at some point, which I'll have to cut and attach to my new stud.

Answer 1

I see no real reason to add in the new stud box to allow for the TV signal cables to have their own cavity. You should be able to simply mount the flange on oneside of the backbox to the stud and use some type of toggle anchor to simply attach the other flange of the box to the drywall. Using this technique you should be able to simply cut two holes in the existing plaster board without having to remove and replace a large amount of material.

I do see two concerns though:

1. It is not up to standard electrical codes to string TV power cords or extension cords up through a wall cavity like you can do with low voltage signal cables. You really should plan to install separate permanent in-wall mains wiring from the existing power outlet up to a new electrical box and outlet that you locate behind the TV.
2. From your pictures it looks like the TV mount that you are planning to use is one that mounts to only one stud. If that mount is an articulated arm type designed to allow the TV to fold out from the wall then I would strongly suggest that you look for another type of mount that installs across multiple studs. If the stud locations are not in a good location then face that wall section with 3/4 inch thick plywood that does span two to three studs and mount the bracket to that plywood.

Answer 2

Yes, throwing data/signal cables down a wall cavity is a standard way to conceal cables for wall TVs. Conduit optional, though in an insulated wall you will need it. You'll want that insulation or else cold will just come sheeting off that wall.

Power cables, different story. You cannot toss a mains power cord down a wall cavity, nor can you intermix it in the same conduit with data cables or low-voltage cables.

Some TVs either run on low voltage, or are capable of running on low voltage. If that is under 55 watts, the low-voltage power cable can be tossed in the same passage as the data cables. Otherwise, no.

The mains power cable must be run via standard wiring methods for mains power.

Some companies make kits which include both portals and a conduit tube between them. Some kits also provide for the mains power, by including a receptacle at the top portal and an inlet at the bottom portal. You then use a short 3-prong extension cord to hop from the inlet to the surge suppressor power strip that your VCR, cable box etc. are plugged into. Hold on, the 1980s just called and wants their "VCR" term back. I mean your DVD pla- hold on, I'm getting another call - your Roku, Blu-Ray, Sling, what have you.