Thread: Cedar bath Japanese style

Hello, this is my first post on Woodworkers forum.

I recently built a Japanese style timber bath for my new house.
I had been thinking about it for a while and after some research into styles decided to go for a simple box style favoured by the Japanese. I did consider an organic form and even a curved end box but felt the rectilinear box form better suited my bathroom and house. At the same time I was considering what timber I would use. I thought Huon pine could work as it is durable and used in boat building, I also looked at bamboo but after keeping samples of both under my shower for 6 months I didn't like the way they both developed black/grey staining. I thought long and hard about finishes and decided that as my bath is next to the shower without a screen or shower curtain it would get a regular wetting from daily showering so an unfinished timber would work best. It was this decision that made me realise that the Japanese bath was really my only option.
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The Japanese bath is traditionally made from some type of Japanese cedar which I presumed would be unavailable (or prohibitively expensive) in Australia so opted for Western Red cedar. This has proved a good choice and after 18 months of service is performing very well. I also made a shower deck out of the cedar that sits in a large shallow stainless steel tray 1.8m x 1.8m in size. This is on an incline towards a corner outlet. It folds up on all sides preventing any chance of leaking and the deck is made in 2 pieces so they can be lifted out for ease of cleaning the tray.

The bath is free standing and drains directly onto the deck so can be lifted and moved for cleaning. The internal dimensions are 1560mm long, 550mm wide by 460mm deep. The wall thickness is 40mm, so overall dimensions of 1720mm long x 630mm wide by 570mm high.

I first butt joined my 75mm wide stock into panels using bisciuts and epoxy glue and then dimensioned them.
Next I machined a rebate along the edges of the end panels. Grooves were then machined at both ends of the inside face of the side panels to take the 'tongue' of the end panels. This was done to allow for differential movement because of the conflicting grain direction of the end/side panel junction. These joints were cut slightly tight. The tongues on both long edges of the end panels were then compressed in my metal vice so they slotted (reasonably tightly) into the grooves in the side panels. This is a typical Japanese technique which allows the joint when wet to tighten up and seal the joint but still allow some movement due to the expansion and contraction of the timber.
I then glued the end panels to the bottom panel using mitre joints with biscuits and epoxy.
After a trial fit I then glued the sides to the bottom panel only using biscuits and epoxy.
A brass bar was then fitted at both ends to hold the tops of the sides together.
An angled marble back rest was then made (an offcut from my kitchen) that is located in small V grooves in the bottom bath panel. As you can see, as it looked like a tombstone I had it engraved to further the effect. Japanese baths being raw timber do not like soap being used in them so this is a reminder for ever more not to use it. Having the shower next to it means one can have a quick wash in the shower whilst the bath is filling and use it just for a good soak.
In practice the bath has worked very well. I has some tannin staining which I like and adds to its character. If you have ever seen old Japanese baths they have a wonderful patina. The backrest, despite concern it would be cold, quickly warms up and is very comfortable. The timber seems to keep the water from cooling with the added advantage that other family members can jump in afterwards without the need to drain the water or add much more heat. It is a very relaxing bath to be in aided by the lovely cedar aroma released when wet. The joints work very well with only a couple of drips before the timber swells.
So in conclusion, if you are considering making a timber bath then I recommend doing it this way.
Happy to make them to order too if anyone wants one.
cheers Tony