What is the minimum height of a japanese bath?
I imagine if we decide to replace the present bath we also need to change the position of the shower controls as they seem too low at the moment.
For the drain, I saw on your website that there are many plumbing options. In our case, I presume the easiest is to have a hard connection simply because there is an existing drain in the centre.
We can make the wooden bathtub as shallow as you want. Consider that for instance if we make it 50 cm high, you will have only about 40cm of inner depth which does not make it a “deep soaking” tub – but apart for that, no problem!
If you want a deeper tub, we could match the height of your niche and you could place a wall-mounted spout in this location feeding it from an extension of the existing plumbing.
This way you could patch the existing tiles and hide it behind the ofuro and spout without the need for a larger tile replacement/repair.
↑ Something like this but placed in the center of the long side.
Generally, we do not recommend to have the drain in the center. This does not allow us to provide a gradient for the bottom plank.
Also, we use a quite retro rubber plug that has a ball chain. Usually, the ball chain is attached to a wall for easy draining of the tub without the need to plunge your arm inside.
In the case of a centered drain, the chain would be obviously in the way.
Another problem you should be aware of is that Japanese bathtubs usually overflow from the top. When the user enters the water there is this feeling of abundance as some excess water flows out and the water level matches the top rim.
We can also supply a drain socket mounted vertically on the wall to act as a western-style overflow but you would lose some usable depth, plus you would have to hide the drain hose in a ledge or similar.
I think the ideal solution in your case would be to place a large waterproof pan to discharge into the existing drain. (something like a Kerdi waterproofing kit)
place the tub on it (without a hard connection) and place some duckboard elements around to hide the larger area of the Kerdi pan which is dedicated to pick the overflow.
The only downside is that the drain is not easily accessible for cleaning so you would have to move over the tub every time.
The good news is that it can be done easily as the tub is very light when empty.
Let me know if this answers your question!