3-Gang surface box over 1-Gang flush?

[xuediao]

I am looking to replace a single socket with a double or triple one, triple would be good to make it more future-proof (it'll only be used for electronics so the 13A fuse won't be an issue).

I know you can buy special conversion boxes that screw into an existing single flush back box. But how are these different from a standard surface box? The former seem to have metal apertures at the back that fix to the metal back box, whereas the latter tend to be all plastic. But the fixing holes appear to be in the same place for a single flush box.

From a safety or practical point of view, is there any reason I couldn't use, for example, an MK 3-Gang surface pattress, attach this over the existing back box, and attach a standard 3-Gang socket? This would be better for matching other fittings in the room.

 

[EFLImpudence]

From a safety or practical point of view, is there any reason I couldn't use, for example, an MK 3-Gang surface pattress, attach this over the existing back box, and attach a standard 3-Gang socket?

That's fine.

 

[sparkwright]

You can get three gang sockets that will go over a flush single box. Without a patress. I think the Clipsal ones do this.

Then again, you did say you wanted MK.

 

[333rocky333]

Unless you use a pvc box with washers then you may find a standard white box fixed with two standard 3.5 screws will just pull off or break without additional fixings

The idea of the metal plate is so you can get sufficient tightness to hold the box secure without additional fixings and without the screwheads pulling through, also the sguare hole gives more room to splay the wires out, saves using a holecutter and im sure the depth is less than a standard box also

Im sure you can also get twins that are all enclosed with just a small rear projection that goes in the existing single box, thus not needing any patress

 

[xuediao]

Thanks for all the replies.

I think I may go back to the idea of a 2 gang conversion back box. I was concerned about possible stability issues if a plastic pattress is just attached with two screws. Also I prefer the symmetry of a 2 gang. I already have one of these boxes and it's 5mm shallower.

I realise you can get all in one converter sockets, but I feel these look a bit cheap, and strange with screws through the middle of the sockets.