I need to fit an outlet like this, into a wall that’s already been tiled and finished.

I’ve got some access to the back of the wall (theres a lift off shelf) above the toilet cistern and I’m planning to run Hep20 pipe up.

All of taps I fitted when I built the house were ‘concealed’ and had a serious metal bracket that was fitted into the wall onto the stud that you then tile around and just attached the chrome parts and spout.

The outlet I’ve got this time just has a threaded piece like an outdoor tap – what do I put into the wall to provide a solid attachment for this?

It’ll be a 1/2″ (maybe 3/4?) tap connector.
The hard part is finding a bracket to secure it.
Maybe something like this could be used, along with a 1/2″ female to female fitting.
Shower connector

Some others here:
More connectors

Wall plate elbow, the fitting that a garden tap screws into.
You could use one of the ones with a pipe attached, might work best.

https://www.screwfix.com/p/hose-union-back-plate-15mm/56415

Invest in some loctite 577 or 55 thread seal to save any messing with ordinary ptfe tape, will mean you should be able to get it watertight and at the correct angle

+1 on the loctite55 ,especially on something like this where you are trying to get the angle right.  I’m sure pros don’t need it but for folks like me it saves a huge about of messing around

Thanks. I think one of those through the wall things is the answer. will mount it to a bit of 75×45 stud and should be able to reach behind and then either bracket it onto the studs to either side (and/or sikafix or grip fill it to the back side of the tiled wall).

Now just need to see if I’ve still get a 30mm diamond hole saw to get through the porcelain tiles. going to be a bit nerve wracking drilling it in place (they’re 1200×600 so no chance of replacing one if I manage to screw it up and we cut them all on the flat when installing. I can’t remember whether I settled on using the Makita cordless or the high speed drill in the end either)

I’m not sure about the loctite. I used it in some places and it worked really well but in others I had more success with just varying amounts of ptfe tape). my bottle’s all dried up anyway…

If you’ve got access to the back you’ll be better off with one of these https://www.toolstation.com/compression-coupler-female/p29289 then put fittings oo to get to where you need, the elbow variety won’t project far enough through the wall as the back nut will hit the back side of the plasterboard.

Alternatively a 1/2″ bsp wing back elbow screwed to the wall and what I’ve listed above without the back nut, screwed into it as an extension. it’ll want to be solid fixed as the weight of your new fitting and the Flex attached to it will make it droop.