Depth of socket metal back box below the surface?

[zumba]

Is there any rule regarding how far the front of the back box must sit from the surface?

I was looking at reusing some of boxes on a different wall, they will sit further back and have about 5 to 10mm extra gap to the surface of the wall.

 

[TicklyT]

There's no limit to how far below the surface they can sit, except for the length of the screws fixing the front plate.

There are longer accessory fixing screws available for deep set boxes.

I believe plasterers prefer back boxes set well below the finished surface so they don't have to work around them, but they may end up 'sunk without trace', needing some cautious probing to find them again.

 

[PrenticeBoyofDerry]

There are no requirements to how deep the boxes can sit within the wall, but as mentioned you may need longer MS screws for fixing the plates.
You could consider filling the void behind the boxes to bring them nearer the surface.

 

[holmslaw]

..

 

[Adam_151]

And if they end up 'sunk without trace' don't panic. As the plaster dries the deeper damper plaster in the box will show up as a damp mark on the drying plaster.

Thats alright if you are there to see it, but often when it happens you don't get back to site until its been all decorated out ready for second fix, and then it becomes a combination of a test of memory and those metal stud detectors sold in DIY sheds...

 

[ColJack]

as long as it's plaster and not plaster board ( ie dot 'n' dab type walls ) then as said, not specific depth..
if it IS a plasterboarded wall then the box should be within the depth of the plasterboard, ie there can be no gap between the box and the board..
that way no wires can get pushed down into the void over the edges of the box accidentally.. that way no damage can occur when the plasterboard flexes a little, when you push a plug in, and it pressing the cable onto the edge of the metal box..

 

[zumba]

Thanks, it's on a brick wall with solid plaster on top.