Finally – A Japanese Bath?

This is something we've been talking about forever – getting a Japanese-style bath built. Finally we can see the light at the end of the tunnel!

Our plan has always been for a large stone tub with a recirculating hot water system. It's to go in the ground floor bathroom, which until a few months ago was just an empty shell of a space. Here's an account of progress so far.

First, I worked on the outer 'dry' area earlier this year – tiling, installing WC and washbasin, etc. No great difficulties there. This is what it looks like (from within the 'wet' bath area):

Then, the first thing to do in the 'wet' area was the drains. Here's the plan:

The large stainless drain unit is from Japan; I couldn't find anything equivalent here or in the UK. The left-hand branch of this drain will be for the bath. You can see it in this photo, where I'm building the formwork for part of the concrete tub structure:

I didn't feel comfortable attempting to pour the whole of the complex tub shape in one go, hence the formwork and concrete pouring was done bit at a time over a period of a few weeks. The concrete is reinforced with a mixture of steel bars and chicken wire. Here's that same section (hollow, to allow the drain out and also to take the recirculation pipes) after pouring:

Next the seat section at the other end of the bath; this was a little more tricky because of the sloping seat back:

Note the double thickness of foam insulation that lines the inside of the tub. We hope to retain most of the heat in the bath water from one day to the next. The final concrete pour was the whole front wall of the tub. (I tied the various poured sections together by extending the reinforcing bars out beyond the poured concrete and tying bars together with wire.)

Here it is with the formwork removed and most of the insulation in place:

I've already installed the pipework for recirculation and have just been working on underfloor heating for the area outside the bath (the shower area). Taps and shower head units have been ordered from Japan, so we are getting close. We are hoping to have the whole thing finished by the end of the year.

What's left to do? Well, I have to seal the inside of the tub. The plan is to use a thin layer of epoxy resin and glass fibre matting. By including some fine sand in the resin, this will leave a key for later fixing slate tiles in place using tile cement. In the shower area, the mortar for the heated floor is almost done, so the next step will be to tile it – and that will be it. The only possible holdup so far is the slate; we haven't sourced slate tiles yet.