How to replace a traditional shower head with a rail shower?

[richard-sydney]

I'm in the process of replacing the shower shown with a rail shower, to improve accessibility.

I've already sourced a rail shower that meets the user's requirements.  The top end of the rail attaches to the water inlet. The bottom end is fixed with a single screw in the centre.

The mixer is in line with the water outlet, and It suddenly occurred to me that the pipe likely goes straight up through the wall which is right where the screw needs to go.  The supplied screw is about 45mm.  The wall is single brick.  The tiles are porcelain, about 8mm.

How deep is the pipe likely to be in the wall?  Is there any way to trace the pipe?

Thanks for any help!

[JacobZ]

Hi @richard-sydney,

It's hard to say how deep the pipe would be in the wall and you can never really know for certain.

You can use wall scanning tools like this DWD181ZJ- 18V Surface Scanner and thermal imaging cameras like this Bosch Professional Thermo Camera to help locate pipes. These tools are quite expensive, so it is probably unreasonable to purchase one for this job alone. 

Simpler stud finders that can detect metal might detect pipes, but not with enough accuracy to be confident.

Considering the potential for damage if you hit a pipe, it's almost certainly worth the cost to have a plumber do it for you. That way, they will be liable for any damage caused and be responsible for fixing it.

Allow me to tag @Nailbag and @Dave-1 to see what they think.

Jacob

[Dave-1]

Good afternoon @richard-sydney 

Im tempted to head towards a professional install also. The depth of where that pipe will be would be hard to determine and I wouldnt be chancing screwing the fixture in and not hitting the piping. If its a pre-made piece within the wall then there may be set sizes of that piece but the installer may have made a custom piece. 

Dave

[Nailbag]

Hi @richard-sydney 

There is always a risk, but the likely hood of a pipe hard up against the back of the sheet is very remote. Especially as most in wall plumbing fixtures are set-back or rebated in to timbers. But there is no easy way to know for sure and as @JacobZ highlighted only high-end scanners will provide both location and depth. 

But I have installed several of these shower rail upgrades and the bottom fixing doesn’t need to be anything substantial depth wise just very secure. So this is how I would tackle it. 

Firstly, how much of the 45mm screw protrudes out the back of the rail fitting? Then subtract around 12mm for the tile and adhesive. Then the thickness of the actual wall most likely cement sheeting. This will give an indication of wall depth before the cavity and how much length of the supplied screw is used. Remembering you don’t have to use it anyway which, I rarely do.

Mark the location of the hole and use a glass and tile bit to get you through to the cement sheeting. I'm a big fan of these Irwin ones for durability. Then switch to a masonry or multipurpose bit to get through the cement sheet. Go slow with minimal pressure and anticipate the breakthrough. A slow speed masonry bit is not going to penetrate and pipe behind. You may even be lucky like I have a few times and strike a stud or noggin.

If not, poke a long nail in through the hole to get some indication of depth before if anything is struck. Chances are you will have a void. I always use these Ramset multipurpose fasteners for pretty much everything these days. They will compress at a shallow depth too and available in both 6mm and 8mm.

Once inserted I use a sharp chisel to slice of the tiny above surface PVC so the insert is flush to the tile. I apply a clear bathroom silicone before fastening the rail.

Nailbag

[richard-sydney]

Thanks gentlemen.  I might get a pro for this one.  Though if a stud finder shows that the pipe is in line with the screw hole,I can imagine even a pro being stumped.

I thought of a possible solution in that case, bolt the bottom rail fixing to a circular mounting plate, then screw the mounting plate to the wall using screws near the edges that will straddle the pipe.  Use countersunk holes and fixings so that everything is flat.  Then the supplied chrome cover plate will cover (at least partly) the mounting plate.  Something like this.

Is it likely I'd find a circular mounting plate like this one in store?  Needs to be corrosion proof of course.  Stainless steel or brass.

Thanks again!

[JacobZ]

Hi @richard-sydney,

It seems like it could work, but there would still be some potential that your screws could hit a pipe. Any time you are drilling into a wall, it's a bit of a guessing game without scanning tools.

I've had a look and unfortunately, there is nothing similar that would be ready to go off the shelf. 

You could likely manufacture something, but to prevent galvanic corrosion, you would need to ensure the metal used is of the same type as any metal that comes in contact with it. It could be a fun project if you are that way inclined, but it is probably more hassle than it is worth.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob