build a niche around bathtub against concrete wall

[a95180]

Hello,

I am going to install a corner bathtub in the basement against two concrete interior walls and plan to build two tiled 12cm deep, approximately 75cm high niches against the walls as a frame. Are there any opinions on which building method/material choice is most suitable/cheapest/easiest? The final surface of the niches will (of course) be tile.

I've thought of these options. Each option gives rise to different challenges.

• Build the niche with concrete blocks against the concrete walls and glue some form of wet room board (humidboard?) using gypsum adhesive (?)
• Same as above but plaster the concrete blocks (with what?) and tile directly on instead of the wet room board.
• Frame a niche against the wall with wooden studs and cover with wet room board
• Glue foam blocks against the wall and glue wet room boards onto these. How do you glue foam to concrete? How do you glue gypsum boards to foam?
• Place ice blocks against the wall and tile directly on these and then have a hollow tile shell when the water melts away..... Okay... let's skip that one

So... is the choice obvious for the average DIY enthusiast? I have no idea at least.

Best regards,
Jonas

 

[eviljava]

I would probably choose option 1 (building with lightweight concrete blocks + wet room board).

It's probably also possible to make it work with some type of stud construction? But I'm not familiar with the other conditions in this basement? If it's an older basement with some moisture migration in the slab, it might not be suitable to enclose wooden studs according to option 3.

Personally, I also like to keep the materials consistent. In a wooden house, I would choose a wood construction (as far as possible). In a space that is fundamentally built of stone, I would, according to the same principle, choose to stick to stone (as far as possible).

 

[Matti_75]

Build it with LP50 steel profiles and wet room gypsum.

 

[a95180]

Without thinking too much, masonry feels like a "no-brainer". Simple and proven, (at least if you like masonry and have the option to mix mortar).

I wouldn't have thought of using LP50 myself, and the more I think about it, the better it gets. It's super easy, cheap, and I get the exact dimension I want for the niche without being dependent on the thickness of the masonry blocks. Thanks for the tips (both eviljava and Matti_75)

 

[scim]

What did you end up doing?

I’m planning to do something similar, you see.

 

[a95180]

What did you end up doing?

I'm planning to do something similar.

Hi!

Bauhaus has waterproof panels they call Do-it. It's a highly versatile composite material available in different thicknesses and not very expensive. Incredibly easy to work with and can be used to build various more or less conventional solutions that can be tiled directly onto.

Cut through the reinforcement with a razor blade. Snap! Glue the parts together with mounting adhesive. Attach the construction to the wall. Tile. Done.

The material itself withstands moisture, but if you use these panels in the wettest zone of a wet room, they should be sealed with foil in the traditional way. But if you already have a tiled wall you're extending a niche on, there might be no need. Tiling onto the panel can be done directly, but if you plan to moisture-seal with film, the panel must be primed. I forgot that, and the moisture-sealing foil could be pulled off very easily. (Tip).

Good luck!