Wall mounted TV - Can I run the power cable through the wall?

peter_333

I'm in the process of wall mounting my TV.  Plan is to run all the cables from behind the TV, down through the stud wall it's being mounted on, so they come out again behind the unit below where the Sky box is.  I'd put a little brush faceplate behind the TV and another down below, to remove cables or add extra ones if needed.

What are the regulations in the UK regarding running the TV power cable through the wall like that?  I guess the low-voltage cables are fine (HDMI, aerial, etc.) but does the power need to be run through a flexible metal conduit or similar?  Or even worse, will I need to add a proper fused socket behind the TV?

tacpot12

There are no regulations that say you cannot do this.

Flex cable installed in this way is not a permanent installation, so even the BS7617 Wiring regulations are silent whether flex cable is allowed. No electrician would  install a permanent circuit in this way, but there is nothing to stop a householder installing cables like this. 

If it is your own home and you know that you won't forget that you have power cables inside the wall so that you don't drilling to them from the other side, it is reasonable safe. 

Ideally, your home will have RCD or RCBOs protecting the circuits that supply the power sockets as this will provide further protection from mistakes when doing other work in the vicinity.

You should try to keep the power cord well away from the signal cables. Bear in mind that you might also have noggins (horizontal timbers) in the wall and may need to open the wall where the noggins are to notch them in two places to run the power and signal cables away from each other. The plasterboard will be easy to refill now and when it is time for the cables to come out. 

I tend to use this conduit on the outside of the wall as it is less work that the above: https://www.screwfix.com/p/d-line-mini-decorative-trunking-30mm-x-15mm-x-2m-white

Don't forget to make sure you can screw the TV mounting bracket into studs; plasterboard on it's own won't take the weight. I sometimes fix a plywood board between two studs and then fix the bracket to the plywood. 

Grenage

Plasterboard can probably handle the weight of a modern TV using hollow wall anchors, assuming studs aren't available.  We recently put a few 65" TVs up and they weigh less than 20kg.  Spread that over one of the wide mounts and it's negligible.

You could just knock a hole top and bottom and feed the power cable and connections through - they'll be out of sight.  I'd install a fused spur and data plate because I abhor a mess.

fenwick458

I really wouldn't recommend using plasterboard fixings for a 65" TV, don't care how much they weigh.

lammy82

fenwick458 said:

I really wouldn't recommend using plasterboard fixings for a 65" TV, don't care how much they weigh.

If not because of the weight, on what basis would you not recommend using them? How is the size relevant?

FreeBear

fenwick458 said: I really wouldn't recommend using plasterboard fixings for a 65" TV, don't care how much they weigh.

I would extend that to a TV of any size. Whilst plasterboard can take the weight of tiles up to 20Kg per square metre, that weight is evenly distributed. A TV mount, the weight will be concentrated in a much smaller area with four high stress points. So either make sure the fixings go in to the studs or put a thick sheet of plywood up (screwed to the studs) to spread the load.

As for the cabling, put some conduit in to feed the cables through - You'll be glad you did should any of them need replacing.

Jack_Cork

I've used plasterboard wall anchors for years and not had any issues with tv's. 

fenwick458

lammy82 said:

fenwick458 said:

I really wouldn't recommend using plasterboard fixings for a 65" TV, don't care how much they weigh.

If not because of the weight, on what basis would you not recommend using them? How is the size relevant?

it was more to do with to cost of the TV, you wouldn't want it dropping off the wall!
I know how much weight plasterboard fixings can take, and in theory they are up to the job, but in practice I often find that if removed and refitted the plasterboard starts to crumble a bit, sometimes they get loose. also depends on the fixings you are using really there is quite a lot to pick from. 
for the extra time it takes to put a bit of wood into the wall I would always do that. I would cut a hole in the plasterboard for a 2G dry lining box, use that to slide a strip (or 2 strips) of plywood into the wall, fix that to the plasterboard, fill the holes with filler and then screw the bracket straight through the plasterboard and into the plywood strip(s).
the hole cut in the wall will then be filled with the new socket for the TV.

Ebe_Scrooge

See, that's what always worries me about plasterboard.  My house is timber-framed, so every wall is plasterboard.  Some of the special fixings you can get are really good, and I use them for lightweight stuff.  But for anything that's got a bit of weight to it, my thought is that even with the best fixings in the world, the plasterboard itself is still pretty weak.  The stud locator that I bought for about 15 quid or so soon after I moved into the house has been worth it's weight in gold :-)

peter_333

tacpot12 said:

There are no regulations that say you cannot do this.

Flex cable installed in this way is not a permanent installation, so even the BS7617 Wiring regulations are silent whether flex cable is allowed. No electrician would  install a permanent circuit in this way, but there is nothing to stop a householder installing cables like this. 

If it is your own home and you know that you won't forget that you have power cables inside the wall so that you don't drilling to them from the other side, it is reasonable safe. 

Ideally, your home will have RCD or RCBOs protecting the circuits that supply the power sockets as this will provide further protection from mistakes when doing other work in the vicinity.

You should try to keep the power cord well away from the signal cables. Bear in mind that you might also have noggins (horizontal timbers) in the wall and may need to open the wall where the noggins are to notch them in two places to run the power and signal cables away from each other. The plasterboard will be easy to refill now and when it is time for the cables to come out. 

I tend to use this conduit on the outside of the wall as it is less work that the above: https://www.screwfix.com/p/d-line-mini-decorative-trunking-30mm-x-15mm-x-2m-white

Don't forget to make sure you can screw the TV mounting bracket into studs; plasterboard on it's own won't take the weight. I sometimes fix a plywood board between two studs and then fix the bracket to the plywood. 

Thanks takpot12.

Looks like two sets of brush faceplates and two conduits (one for mains power and one for low-voltage) are the order of the day.

As for mounting, the TV bracket is already on the stud, nice and secure.  Just got to figure out if there are any noggins I'll need to get the cables around.

Mutton_Geoff

When you mount a TV flat to the wall, the stress on the fixing is almost all in shear unlike a shelf where it's trying to lever the fixings out of the wall. Plasterboard can take a heck of a lot of shear loading although I'd still prefer to be fixing into timber.

For retrofit work, a single piece of trunking running centre straight down painted the same colour as the wall is 10x easier and will become hardly noticeable in time.