Bristan Concealed Shower Install help requested

[FiremanT]

I am about to order a shower kit:

Bristan Descent Luxury Fixed Head Shower Pack

QS-V694 MFC CODE: DESCENT SHWR PK

Bristan Descent Luxury Fixed Head Shower Pack - DESCENT SHWR PK

I am a gas service engineer, not a plumber. Although I can obviously do plumbing to a certain degree, it has never formed part of my regular work.

I intend to fit the valve, then finish the plasterboard, followed by shower wall panels (which are 10.5mm).
This has now now occurred to me:
the valve needs to be attached to the stud work, obviously. The spines will then protrude through the depth of the board & panel. Does the valve have to be fitted at a precise position as far as depth is concerned, or is there reasonable leeway? There must be a maximum thickness of wall covering allowed, any idea what that will be?

The second issue is similar: the wall outlet will NOT be accessible from behind, and the instructions​

2016-8-27--8-52-51-639. PDF-1111034-1-D5-2 (2).PDF

show an alternative fixing method i.e. not using the back nut and simply screwing into a 1/2 " female fitting, with an 'o' ring between the wall panel and the outlet. Does this 1/2" fitting have to be fitted in a precise position? I am struggling to understand what will stop it flopping around once the outlet is screwed into the fitting, unless the water tight position is reached when the outlet is tight against the wall panel, if you see what I mean.

Finally, are these units okay?

Thanks for any help.​

 

[Madrab]

With these units you need to be reasonably accurate with your distances. With the wall open you need to offer the valve up and see how far out you want the controls and therefore how deep the mounting needs to be for the valve screw holes. Don't forget the wall covering and any adhesives needs to be added to the dimensions.

If you want to use a female elbow for the wall outlet, then you would be better advised to use a wall plate elbow and screw that to a brace in the wall. You can then use some PTFE Tape/Thread and screw the outlet in as you would attach an outside tap. You need to be confident to use the correct amount of thread seal to make it watertight.

I use gas PTFE tape and give it 7 wraps best to give it a dummy run before the wall is all sealed up.

 

[FiremanT]

Thanks Madrab. You have pretty much confirmed what I thought. Would you advise, or not, to use this unit - or do your comments apply to any (as I would think)

 

[denso13]

Would you advise, or not, to use this unit

Bristan are pretty decent, never had many issues with them.

 

[Madrab]

Bristan, IMO, are a good midrange manufacturer FT, insofar as they have good support and they have spares available for all their products, so when it's time to service then parts should be available. The trick with these are, make the opening suitable enough whereby if it or bits of it need to come out then it can without wrecking the wall.

I wouldn't have any issues installing any of their stuff.

 

[FiremanT]

With these units you need to be reasonably accurate with your distances. With the wall open you need to offer the valve up and see how far out you want the controls and therefore how deep the mounting needs to be for the valve screw holes. Don't forget the wall covering and any adhesives needs to be added to the dimensions.

If you want to use a female elbow for the wall outlet, then you would be better advised to use a wall plate elbow and screw that to a brace in the wall. You can then use some PTFE Tape/Thread and screw the outlet in as you would attach an outside tap. You need to be confident to use the correct amount of thread seal to make it watertight.

I use gas PTFE tape and give it 7 wraps best to give it a dummy run before the wall is all sealed up.

Thanks for the comments. I went for it in the end, although only half fitted, and have been pleasantly surprised with the weight and perceived quality. I was concerned that the "chrome" may actually be plastic, but is metal, presumably brass. There is actually at least 30mm tolerance "back to front", achieved by the facia fitting snugly over parallel tap shrouds. So the extent to which the shrouds project into the shower area depends on the position of the valve. So very happy. Thanks again.