I'm about to plasterboard a wall for the first time...

[Fireraiser]

I have 2 surface mounted electrical sockets on the existing wall. I want those to be sitting flush when I've finished. I understand that I need to remove them, cut holes for the new recessed back plates, fit the plasterboard and Bob's my uncle. But what I can't work out is how I work out exactly where to cut the holes. Do I just measure from the floor to the centre of each socket and from the edge of the previous board to the centre of each socket and work it out from there - or is there a better way?

TIA

<edit> I'd got the order of cutting the holes and fitting the board the wrong way round </edit>

 

[SFK]

Fireraiser,
I bet others have better ways of doing this, but as a DIYer I use "Dry Lining Boxes":
https://www.screwfix.com/c/electrical-lighting/dry-lining-box/cat830524

I mark on floor or measure where cables are along wall, fit plasterboard and then carefully cut a hole in plasterboard, pull cables out, feed into Dry Lining Box, push Dry Lining Box into hole.

Using this method the hole positioning only needs to be accurate to a few cm.

Then fill Dry Lining Box with a square of Cardboard covering the cables so when plasterers skim the plaster it is easier to the plaster that has filled the Box out without it getting all over the cables (I do this just before plaster has fully dried).

ps, if the plaster board is very close to wall, you may need to still knock a hole in the wall for the Dry Lining Box to recess into

But I am now interested to see if there is a better way?
SFK

 

[terryplumb]

Usual way would be to remove existing sockets. Fit galvanised box's. Then measure up boards and cut openings in relative positions in boards. Then fit the boards. The cables would be inside the galv boxs , connected as appropriate and insulated .after plastering the new sockets would be fitted.

 

[terryplumb]

Cutting holes in plasterboard ,when you know cables are lurking behind where you are cutting ,is just asking for trouble and risks damaging the cables.

 

[SFK]

Terry,
yes good point. I was lucky in that I has 1inch behind the plasterboard, and I had coiled cables to one side/above before fitting plasterboard.
So had enough space to get fingers in and pull it down once I had (very carefully in case cable had moved) made the hole.
SFK

 

[Fireraiser]

Cutting holes in plasterboard ,when you know cables are lurking behind where you are cutting ,is just asking for trouble and risks damaging the cables.

I had planned to cut the holes before fitting the board

 

[Fireraiser]

So what are the relative merits of https://www.screwfix.com/c/electrical-lighting/back-boxes/cat7230011#category=cat2470003 vs https://www.screwfix.com/c/electrical-lighting/back-boxes/cat7230011#category=cat830524 ?

 

[terryplumb]

I had planned to cut the holes before fitting the board

******
I was referring to SFK ' s method of fitting the board ,then cutting it Fireraiser

 

[Fireraiser]

******
I was referring to SFK ' s method of fitting the board ,then cutting it Fireraiser

Sorry.

 

[SFK]

Fireraiser,
Your two links show the same products.
So I will presume that you mean what are merits between Metal and Plastic.
Note that my preference (all as a DIYer) is normally for metal, but there are times when I use plastic.

Metal Back Box:
Pro: Stronger
Pro:Better to screw into.
Pro:Feel more secure in wall.
Pro/Con:Need secure fixing at rear of box.
Recommend: always use 35mm deep boxes, never 25mm
Con: Might need to make hole in back wall to ensure metal rim does not stick above plasterboard (I always find it a bit hard to get depth just right), but better a few mm too deep than above plasterboard.
Con: Also need to buy PVC grommets to ensure sharp edge of box does not cut wire. https://www.screwfix.com/p/schneider-electric-pvc-grommet-open-pack-of-100/11833


Dry Lining Box:
Pro:Needs only secure plasterboard at sides to fix onto.
Pro: Easy to place onto stud wall
Con: if you make hole too big can wobble a bit.
Con: must not put too close to Stud otherwise will not clamp onto plasterboard
Con: Obviously does not work on solid walls.


SFK

 

[roy c]

You can put your plaster board up to the wall and make an inch hole in relation to where the cable is and pull it thru. Before you fix board that will be the centre of your socket. Of coarse you will have all the studs marked out where they are on your board with the board in its position and measure up your heights for centres and distances between each socket. (don't go wild and make an artists master piece !!! Just one line for centre of stud and a pencil line of centre of boxes) So poke wires thru before you fix... Good Luck..

 

[23vc]

Offer the board up, couple of whacks with the lump hammer and a bit of 4x2 where you think each box is, leaves the imprint on the back, cut out accordingly

 

[pilsbury]

I shall be doing this soon. I was going to use 23vc suggestion but rub a bit of string line chalk on the edge of the back box to leave a mark.