How to fit a metallic back box on a stud wall?

[lilimop]

Hey everyone,

I'm trying to understand how to fit a metallic back box on a stud wall. Should it be fixed to a stud (on one of the sides) or is it expected to be fixed to a noggin?

In either case, how would I know exactly where a noggin or a stud is, so that the hole I cut on the plasterboard is perfectly aligned with it?

I have a stud detector, but there is always a degree of error, so I'm not sure how I can find these in the wall. I wanted to avoid using the plastic back box that clips on the sides.

Thanks!

 

[Moley]

TLC have them listed.
Plus a few extra words!!!

 

[davesparks]

I have fitted many of these in the past, but haven't seen a new one offered for sale for years.
Are they still available?

Yes the ones for use in fire rated walls are metal with an intumescent pad in the back of them.

 

[brianmoooore]

Things I'm referring to were a standard 35mm metal box, with a flange welded on outside, each side, about 10mm from the front, and with a 3.5mm threaded hole in the middle of the back.
You cut out a standard sized hole in the plasterboard, glued a wooden block to the inside of the opposite inside face of the wall, inserted your box, and secured it with an appropriate length of 3.5mm bolt through the hole in the back onto the wooden block.

 

[davesparks]

Things I'm referring to were a standard 35mm metal box, with a flange welded on outside, each side, about 10mm from the front, and with a 3.5mm threaded hole in the middle of the back.
You cut out a standard sized hole in the plasterboard, glued a wooden block to the inside of the opposite inside face of the wall, inserted your box, and secured it with an appropriate length of 3.5mm bolt through the hole in the back onto the wooden block.

I've never seen that, I've used the little metal wings you clip on to the outside of the box and then have to somehow hold the box in place whilst doing up the plate screws.

 

[westward10]

MK made the little metal wings to fit the back boxes.

 

[brianmoooore]

MK made the little metal wings to fit the back boxes.

Yes, I keep them in stock. Can be used to fit a box tight against a stud. Use a couple of wood screws to fix one end to the stud and the Mk wing on the other end.
If I know I'm going to need one the next day, I've been known to tack weld a wing in place on a box the previous evening.