(France) Shower upgrade question

[tinpanalley]

We've moved into a place and there's a bathtub with handheld shower hose connected to the faucet, as is typical in bathtubs here. Then they've just put a shower head holder on the wall. So we want to install a shower column without taps.

What I want to install:
I got this, and it's perfect, but now I'm afraid it feels heavy. Is that a thing, a shower assembly being too heavy for a wall?
The whole thing when assembled is 2.4kg. The overhead shower head, which is the one if you look at the images below that protrudes out, is 1.45kg alone. So that's what I'm dealing with, but I know the integrity of the wall and the type of force is more important than the weight capacity of the anchors. On wet sponge, anchor tolerance is pointless.

Just did a wall measurement in an empty part of the wall and the wall is 1.75cm / .75" thick, the gap between the shower wall and the next one is 4.5cm / 1.8". And the tiling is about .6-.7cm thick. But the plastic toggle bolts I have need about a half inch hole and I don't wanna do that in a shower.

What anchors do I have:
I've got good quality 40 and 30lb DuoPower anchors I use (yes, they're North American though we live in France, we've moved recently...). I just didn't know how much tension load would affect this installation.

So, I'm confused about whether this all sounds fine with my anchors, do I need something else, is any other info needed to help me out?

The device:

 

[yorksbuilder]

Give more clarity about the wall construction and then we can advise accordingly. Is it plasterboard, cement board, wood stud or metal stud, is it brique (hollow terracotta)?

 

[tinpanalley]

Give more clarity about the wall construction and then we can advise accordingly. Is it plasterboard, cement board, wood stud or metal stud, is it brique (hollow terracotta)?

I genuinely have no idea. But.. I've taken a couple of photos with my endoscopic camera and a video. No clue what I'm looking at. Did I just happen by chance to find myself in this hexagonal air pocket in the wall?! And what is that material? Some kind of internal foam? All I see when I turn/rotate the camera in there is the same white material. I was hoping to see a stud in an empty wall that I could aim for from the outside.

Here are the photos and a video.

 

[yorksbuilder]

Looks like hardboard with egg carton internal. Not really suitable for a bathroom, I'd recommend ripping out and refitting cement board or at a minimum moisture resistant placoplâtre before hanging your shower on it

 

[tinpanalley]

Looks like hardboard with egg carton internal. Not really suitable for a bathroom, I'd recommend ripping out and refitting cement board or at a minimum moisture resistant placoplâtre before hanging your shower on it

Right, well that's not gonna happen because this is a rental in a rather prized apartment residence actually. Surprised to find this may be inadequate materials.

 

[foxhole]

If it’s tiles where you need to fix then the tiles will provide enough support to hold any shower rail. But changing it to that rail will increase the water hitting a wall not designed for a shower leading to early failure .

 

[tinpanalley]

If it’s tiles where you need to fix then the tiles will provide enough support to hold any shower rail. But changing it to that rail will increase the water hitting a wall not designed for a shower leading to early failure .

How so? The water showers down into the tub, not against the wall. In fact, what is there now is a simple holder for a shower head that one is meant to put up on the wall.

 

[foxhole]

How so? The water showers down into the tub, not against the wall. In fact, what is there now is a simple holder for a shower head that one is meant to put up on the wall.

Currently you have a holder on the wall , it’s just there so you have a flexible shower head to wash your hair etc. It’s not intended for use as a shower , while the one you intend to use is a waterfall style fitted overhead which will splash in all directions when in use .

 

[tinpanalley]

Currently you have a holder on the wall , it’s just there so you have a flexible shower head to wash your hair etc. It’s not intended for use as a shower , while the one you intend to use is a waterfall style fitted overhead which will splash in all directions when in use .

Ok, so you're saying the wall built around that tub will have actually been installed without concern about any kind of water resistance because the tub was never intended to have water spray towards the walls with any frequency? So how is one supposed to use that shower head on the wall and rinse one's head without splashing?

 

[foxhole]

Ok, so you're saying the wall built around that tub will have actually been installed without concern about any kind of water resistance because the tub was never intended to have water spray towards the walls with any frequency? So how is one supposed to use that shower head on the wall and rinse one's head without splashing?

It’s intended for use at low level , with care. Heavy soaking of an unprotected plasterboard (drywall) with soon allow water through grout ( it’s not waterproof) .
If you want to use as a shower a 360 shower curtain is needed to protect from splashing .
One example of 360 rail .

 

[tinpanalley]

It’s intended for use at low level , with care. Heavy soaking of an unprotected plasterboard (drywall) with soon allow water through grout ( it’s not waterproof) .
If you want to use as a shower a 360 shower curtain is needed to protect from splashing .
One example of 360 rail .

Ok, I'll take that into consideration. I'm trying to reach out to forums where there are local tradespeople who can maybe identify what this wall is and what it can handle. I don't terribly mind the 360 shower curtain idea but the mold and mildew build up is an annoyance. Is there nothing I can do to make the grout more impermeable or resistant?