I just had a meeting with the water filtration/circulation technician.
1. Do you recommend to install hydrotherapy jets with 6-persons hinoki tub?
2. How do you suggest we deal with the overflow?
1)As you know, japanese onsen are usually not equipped with jets.
Often there are some shallow “bed type” jacuzzi tubs for individual use.
Some people may feel that japanese bathing has a precise ritual and aesthetics and does need the bubbles. Others may appreciate the jets as an upgraded and more luxurious japanese tub.
This choice depends on your clientele and on the services that you offer in your establishment.
If you decide to use jets, there is no incompatibility with wooden tubs. Anyway we would recommend you to ship us the nozzles so we can seamlessly embed them in the locations as per your instructions.
Many small air outlets on the bottom of the tub (air-blower) are not recommended as they weaken the structure of the tub.
2) Overflow: of course the whole floor will be waterproof and with a floor drain.
I suggest 3 options:
a) to have a gutter 10mm deep x 100mm wide all around the tub with a floor drain inside
b) to provide the tub with a top overflow cut and direct the water towards a side of the tub equipped with a floor drain
(see example here: http://www.bartokdesign.com/japan/7-custom_ofuro/ofuro_for_new_zealand.php)
c) to insert the tub into a recessed floor area equipped with the drain. The water can be recessed just 10cm to cover the bottom apron or can be recessed up to the top border, it depends on your layout.
(see example here: http://www.bartokdesign.com/japan/0-blog_news/hinoki_slanted_bathtubs_in_res.php)