Lighting Cable & plasterboard

[DavePrior]

Hi - complete idiot here.
I am re-siting a bedroom light switch onto a stud wall, which is between the bedroom and the bathroom. I\\\'m told that I have to do something special with the cable, since it is going between plasterboards, and particularly because the wall is shared with the bathroom. Help please !

 

[Big_Spark]

Hi - complete idiot here.
I am re-siting a bedroom light switch onto a stud wall, which is between the bedroom and the bathroom. I\\\'m told that I have to do something special with the cable, since it is going between plasterboards, and particularly because the wall is shared with the bathroom. Help please !

So long as the cable is within the walls structure your OK.

As it is a dry lined wall, I would suggest that you put a nogin in the wall were the switch is to be located so it has a firm fixing. Dry lining boxes are ok, but nothing is a substitute for a good fixing on a bit of timber.

 

[DavePrior]

Nice one - thanks indeed.

 

[white_tiger]

Doing something similar myself.

I've rehung some doors, so the light switches need relocating to the opposite side. I'm resonably sure I can mount the switch & do the wiring, but actually getting the cable from the loft to the switch is the tricky bit.

Firstly, I need to determine where the wall cavity is from the loft - all I can see is the plasterboard ceiling & the rafters. Should I expect to be drilling through wood &/or plasterboard?

Secondly, & more tricky - how do I get past the nogins between the ceiling & the switch? All I can think of is making some grooves in the plasterboard to pass the cable around them. Some filling work best avoided! It's also difficult finding the actual location of the nogins just by tapping on the walls & listening for a change in sound.

If anyone can help - thanks!

 

[AdamW]

First thing, old post! Start a new thread when you want to ask a question.

What you should see from the loft is wood, the "head-plate" I believe it is called in stud-wall parlance.

To get "around" noggins, you actually go THROUGH them. You make a hole in the plasterboard big enough to get your drill in there, drill vertically down through the noggins. This is easier with a right-angle drill, but such a tool is by no means essential.

Then you patch and make good. Sorry, looks like there will be a bit more to it than a bit of polyfilla!

To locate noggins you can use a "stud detector". These are often built into wire-detectors and detect the change in density when passed over the wood framework instead of just plaster.

 

[AdamW]

Just a thought, if the wall was put in after the ceiling (e.g. in a re-arrangement or division of rooms) then you would possibly see just plasterboard from the loft. In which case you can use your newly-acquired stud-detector from above, or alternatively drill a small hole in the ceiling either side of the wall to use as markers. Drill your cable hole exactly in between them.

 

[white_tiger]

Thanks for the response & the telling off for posting incorrectly

I'm put off by the idea of making some holes in the wall large enough to get a drill into, as patching big holes in plasterboard sounds like a nightmare! But if that's the only way.......

I don't think the walls have ever been altered, so I guess there should be a head plate, as you suggest.

Annoyingly, my wire detector doesn't have a stud detector as well. Another visit to the diy shop!

 

[felix]

You can find the top of your partition wall by careful measurement up in the loft. When you drill through you'll hit wood. To be sure you hit the centre, drill small (2mm) test holes off to each side until you come through the ceiling. These will be easy to patch up later.

My trick for noggins is to use a hole cutting saw bigger than the noggin thickness. Find the exact centre of the noggin with those test holes then use the saw to remove a circular piece of plasterboard. Preserve this to refill the hole afterwards.

You should now be looking at the full thickness of the noggin with a small gap top and bottom. Now drill a line of holes down the noggin wider than the cable and chisel out the rest. It helps if the hole size matches your chisel. This will give you a slot for your cable.

Once the cable is in you can glue a piece of wood into the slot to restore the structural strength of the noggin and keep the cable away from the surface. Glue the disc back in and fill the saw cut. Job done.

 

[Scoby_Beasley]

Alternatively, a wood bit like this and some extension bars like these straight down between the partition wall using smaller wood bit every time you hit a stud (2 at most ?). Grrrreat fun in the loft with a wire coat hanger etc !!

 

[white_tiger]

Cheers felix!

And Scoby_Beasley!

 

[white_tiger]

Thanks again for the help.

I got lucky - there were no noggins between the head plate & the switch locations.

Basically, it has cost about £6 per switch alteration - new switch, wall box, junction box, blank plate & cable.

Well pleased, jobs a good 'un!

 

[Scoby_Beasley]

Thanks again for the help.

I got lucky - there were no noggins between the head plate & the switch locations.

Basically, it has cost about £6 per switch alteration - new switch, wall box, junction box, blank plate & cable.

Well pleased, jobs a good 'un!

Awww! Think of the fun you missed out on trying to feed the cables through though !!