by 333rocky333 »
Wed Jan 23, 2008 9:56 pm
With domestic .As far as I know.
Metal boxes have been around in walls for years , wiring used to be earthed via metal pipes, so the metal box provided the earth and had a terminal in it to connect a earth link to your socket .
Lighting however was unearthed then so the surface boxes were not metal for safety and usually to save cost of chopping in.
Sockets then became surface on the skirting boards,
and just evolved into the present type which are dual purpose flush or surface with a matching box if wanted.
with new building designs using more twin and earth and plasterboard walls, makers cashed in by making the plaster fix boxes to fit faster, with no need for noggings etc.
You could just mark them and the dry liner would cut the hole for you .
As the earth was now contained in the wire it was logical and cheaper to make them from plastic.
Metal pipe also became replaced with more plastic so surface plastic boxes became the norm.
White to match the switches etc
The only real advantage now of the steel boxes in the walls are the one adjustable lug.
As you dont have to worry to much if the builder plasters it it in wonky
As yet I dont know any plastic box that you can adjust
And dry liner boxes wont fit in a wall well due to the design
Invent one for dragons den, you could be quids in
Not sure if i can say, The Iee are doing a peice on the history of the plug and socket going back years,if you can find it