ᐅ Building a Whirlpool Bathtub Yourself – Seeking Opinions on the Project

Hello dear forum community,

My wife and I have bought a small old house.
The upstairs bathroom is going to be renovated first.

Since we both really like unique designs and wellness features, we want to install a whirlpool bathtub.

We find the standard white off-the-shelf models not only unattractive but also beyond our budget.

I would like to hear some opinions (preferably from experts who have done something similar) on my following idea:

- Remove the screed in the area where the tub will be
- Seal the area with a waterproof membrane for safety
- Build/mold the area about 15cm (6 inches) larger than the final tub size
- Embed the drain and air jets made of copper tubing into the Ytong (aerated concrete) structure, guide them upwards along the side, merge them behind a cladding above the waterline, and lead them through a thick pipe to the pump
- Then mold the final shape using waterproof concrete (WU concrete)
- Finally, tile the entire surface with mosaics

What do you think about this?

I would also appreciate book recommendations or similar resources.

Best regards,
Christoph