Deeper back box for electrical socket

Schizophonic

Schizophonic

Schizophonic

Soldato
Joined
27 Dec 2006
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Northampton
So I have a Knightsbridge fast charge USB and its a bit of a thicccc boy and tried installing over the weekend and its quite cramped behind it and think I need to have a deeper backbox.

How easy is the job to replace the back box?

I have in a newish house (built in 2000) and where the socket is located is on the top floor next to bed room, its currently a 25mm back box I believe and the cables come from the bottom. If I get a deeper backbox I know I'll have to make adjustments but I want to know whats best to get as I've seen there are different types of back boxes from the conventional metal and then the plastic dry wall ones.

https://www.toolstation.com/appleby-dry-lining-boxes/p96918

https://www.toolstation.com/metal-box-2-gang/p77591
 
Depends on your wall, if you have brick you will need the metal, if plaster, you will need the plastic.

In terms of difficulty, the metal one would need you to unscrew the back of the 25mm and pull it out, this might be difficult depending on the plaster overlapping the edges, you will then need to hammer and chisel the back of the box to make the hole 35mm deep, then fit the new 35mm box.

Plaster boxes are easier as you loosen off the screws and the side clamps unclamp the box from the wall and then just place a new one, a lot of modern houses don't have any skim coat on the plasterboard, they joint the joins with tap and easifill over them! So other than paint, shouldn't be much of a join overlap holding it in.

Personally, I would just get something like the LAP range from screwfix that fit a 25mm backbox.
 
Andreworex said:
Depends on your wall, if you have brick you will need the metal, if plaster, you will need the plastic.
Click to expand...

Thanks, I know its plasterboard but I think it will have to be a like for like replacement but deeper backbox.
I only quoted toolstation as I can get a staff discount :D but then its only pence

My next concern, as I'm messing with live wires I'll off course switch off the mains but I can't do too much harm if i handle the cables with care and use a rubber grommet where the cables would go into the backbox.
 
toolstation are good, you will need the plastic one, its and easier job than the metal!

always turn off the mains or the RCD for that loop if you know 100% which it is, if in doubt turn the main isolator off.

reuse the old rubber grommet, you will be amazed how many don't use those grommets ;)

make sure you don't let the cable fall into the wall if its plasterboard and coming up from floor to socket...! then its just colour matching :) nice job swapping a socket.
 
Andreworex said:
toolstation are good, you will need the plastic one, its and easier job than the metal!
Click to expand...

I'll look to get that when I'm brave to tackle this (simple job)
Looking online to see how internal walls are built in modern houses



I'm assuming mines very close but will see how the back box is attached to the wall....and also you got me worried the cabling falling into the plasterboard....will secure it. Dont want it falling
 
Schizophonic said:
I'll look to get that when I'm brave to tackle this (simple job)
Looking online to see how internal walls are built in modern houses



I'm assuming mines very close but will see how the back box is attached to the wall....and also you got me worried the cabling falling into the plasterboard....will secure it. Dont want it falling
Click to expand...


Assuming it's just a normal plug socket (especially 2 gang) then it should be a breeze to do.

I had an absolute nightmare doing mine, although it was for a 1 gang double light switch - was also the landing, so i think it also had a wire going back to the downstairs switch. All in i think there was maybe 7 T&E wires feeding into the backbox. How on earth the original electrician managed to install it god only knows, but i'm labelling him a cheapskate for not just going with a slightly deeper backbox for the sake of a few pennies.
 
dLockers said:
Save yourself the time and effort and get a spacer for the socket itself.

Especially given the shelf life of those USB plugs is about 12-18months with the advancements in USB charging being a lot smarter than dumping power down a wire.

https://www.screwfix.com/p/schneider-electric-lisse-2-gang-spacer-white/2105j
Click to expand...

pepp77 said:
If replacing the actual back box is difficult you could just try something like thi s- https://www.amazon.co.uk/Schneider-...rds=plug+socket+spacer&qid=1611654450&sr=8-11

It is what I used when I couldn't replace my backboxes to put USB faceplates on.
Click to expand...

I didn't know these existed. I might try this first to see how much more room it gives me to play with. If it works out then I might get more of these usb fast charge plugs around some of the double sockets around the house I might use and do that rather than extended back box. I know I should do it properly but considering the possible work involved, chiselling, filling, sanding and etc - i rather use a extension faceplate which would stick out a few mm but save me from making a hash of it all.
 
Schizophonic said:
I didn't know these existed. I might try this first to see how much more room it gives me to play with. If it works out then I might get more of these usb fast charge plugs around some of the double sockets around the house I might use and do that rather than extended back box. I know I should do it properly but considering the possible work involved, chiselling, filling, sanding and etc - i rather use a extension faceplate which would stick out a few mm but save me from making a hash of it all.
Click to expand...
Much cheaper, more effective and sustainable solution. USB face plates will never keep up with Anker/USB charging standards.
 
Andreworex said:
always turn off the mains or the RCD for that loop if you know 100% which it is, if in doubt turn the main isolator off.
Click to expand...

You should also use a tester to make sure it's actually dead. Not likely on a 20 year old house I grant you (unless it's had an extention). But there could a 2nd consumer unit, it's also not completely unknown in flats or terraced houses to end up with a socket that's been wired to wrong supply.

Also if you have PV panels make sure they're isolated.

EDIT: The other thing that can go wrong is at some point between the meter and the consumer unit the Line and Neutral get swapped. Most circuit breakers only disconnect the line and not the neutral. However if these are the wrong way round then a circuit that appears to be isolated is still live at 240 volts.

Here's the very amusing David Savery explaining it all.
 
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Just take it off and see if there's space behind it for a deeper back box. If there is the whole job is as difficult as unscrewing and screwing some cables and a box in.
If it needs to be deeper then either use a spacer as mentioned before or chase it out to fit a deeper box in. Ideally with a chisel bit and sds drill. It's doable by hand too, just a faf.

Obviously make it electricaly safe first.
 
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