Homemade, Deep Soaking Tub

IDK how "permies" this topic may sound but I guess if we can discuss cloaks and shoes, this is game:  We are a tall couple and our bathtub is an old cast iron one with feet; yes, charming, but made for someone Shorter.  It is time to replace it, and I want to use either a pre-made trough or some other repurposed deep container to make a Japanese-style, vertical soaking tub that will accommodate a tall person above the shoulders.  We keep our home minimally heated in Winter, and sometimes turn on the AC in Summer, so a soaking tub would provide some relief from the elements, as well as just being good for balneotherapy. (A Hot bath can be as good for you as a sauna!).

Has anyone done this kind of thing?  I am leaning toward the Rubbermaid-type trough for toughness and the fact that it wouldn't rust or need coating; but it's black, and plastic...and there is the question of how to drain it adequately...

Has anyone done this?  I am betting there is some good info out there...for which, thanks in advance!

We ended up buying an expensive steel one, but in the process of shopping for it, we took note of the fact that wooden tubs are sold and it made me think that coopering one ourselves couldn't be too impossible. We ended up going the way we did because we could afford it and we didn't want essentially a shower-pan for the tub to sit in to handle weeping leaks through the tub during the constant filling-drying process.

Not sure which approach will be best for you.. but I swear by the hot bath soak. Twice a day.. everyday. Mine happens to be from a natural hot spring. Regardless of what you decide, you are on the right track!

Could you plumb up a livestock watered from Tractor Supply?

An old church I used to go to did baptisms in them. They are cheap and easy to plumb.

Thanks, Steve; yes people have made Youtube vids of stock tank ones; I would like a more deep and vertical one but we may go for a stock tank.  The Rubbermaid ones can actually crack (we used to have grass fed beef cows and we have 2 leaky ones) but perhaps as a tub it wouldn't; generally people put an epoxy liner inside the galvanized ones...but I am just thinking, there must be something else out there that would be more vertical...and also cheap XD

Ted, you are a lucky guy!!  - let me now your address, I'm comin over, me and my rubber duckie

Betsy.. just take a right turn at Death Valley and look for the steam.

There was a fairly deep Rubbermaid stock tank abandoned on a property we bought. In my dreams, I want to get a greenhouse built, and put the stock tank in there for deep soaking in, but where the humidity and heat will stack functions with the plants and solar gain. It is already plumbed for use as a pond filter, but if I want to make good use of the water I suspect I'll need to build something sturdy to give it a little height. I'd also have to figure out how to heat it - no convenient natural hot springs in my neighborhood!

However, I'm not a particularly tall person. I'm not sure it would be deep enough or that you'd feel you'd have enough leg room. I can just imagine you now, visiting a farm shop and climbing in all the stock tank options trying to find one that's deep enough!! As I'm getting old, I was actually planning on a low stool partly supported by a ledge that sticks out above the outlet. I figured I'd still be able to get my shoulders covered, but only just.

Looks like there are probably some water tanks that might work. Not sure what price range you're hoping for, though.

https://www.nationalstoragetank.com/product-category/plastic-tanks/rain-harvesting-tanks/

https://www.capitolwatertanks.com/shop/233-gallon-galvanized-metal-slimline-water-storage-tank

I know you said premade, but if you can't find the right tub, you could make a ferrocement one.

If you don't want the ugly plastic look, you could make a wooden barrel facade around the exterior or something like that.

Betsy said, "It is time to replace it, and I want to use either a pre-made trough or some other repurposed deep container to make a Japanese-style, vertical soaking tub that will accommodate a tall person above the shoulders.

In order to get this tub deep enough to accommodate a tall person up to the shoulders this tub will need to be fashioned from wood or something like concrete.

Stock tanks do not come that deep.

When I lived in Mexico the house had a tub that had been made from concrete and tile.  It was very pretty.  I would not have any idea how to make one.

I can vision a tall soaking tub made like that tub though.

Concrete is not a very permie thing from what I have read though it is a solution.

Here are some I found on Pinterest, (of course these are regular tub to give you an idea how one can be made):


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Here are some wooden tubs:


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I also found some threads that might give you or others some ideas:

https://permies.com/t/14958/Great-ideas-indoor-person-soaking

https://permies.com/t/49111/Rocket-hot-tub-skids-Wheaton

Jan, thanks for those links: I like the galvanized one but for $2K it is easier to buy an expensive premade tub...but I LOVE the tiled one; if I can get someone to make me a concrete tub and tile it I'll be very happy!!  

You can get a bathtub that is a 'soaking' tub.  Maybe a little deeper, I don't remember, but the overflow is situated higher on the tub.  We got ours by chance off craigslist $200.  Plugged the outflow with a rubber stopper, drilled a hole for the Chofu inflow and used the bottom drain as the outflow to the Chofu.  Used fence board discards from our fencer friend, planed them and could not believe how beautiful they are once planed.  Hubby is 6'5" and we both fit up to our neck, head to toe.  With tub overflow blocked, water goes all the way to the upper edge of the tub.  When we empty the tub, it feeds the swale that waters the front garden.

In my early 20s living in an old 10'x40' mobile home, we had to renovate everything to make it live-able. (The mobile home had not been lived in for several years and had been parked in a field). The bathtub was tiny, but by moving things around in the bathroom, we made space to build a large rectangular tub out of wood and plywood, water proofed it with pond liner, and then tiled it. It worked, sort of, but tiles kept popping off, probably because the wooden framework was a tiny bit flexible. The tub was pretty while it lasted.

Eventually we gave up and replaced it with a plastic bath that at least was larger than the original. Using a wooden framework to build a tub was probably a dumb idea, but we were kids and you learn by trial and error. Something like ferrocement would have been out of the question due to weight on an already rickety floor (we didn't want to end up sitting in a tub underneath the trailer). It was probably 30 years later that I first heard about aircrete. If I were young and energetic again, with such an ambition in mind, I'd possibly give aircrete a go. Knocking up a balloon the right shape as an interior mould would probably not be too hard. Could be a bit of fun actually. Aircrete is also not such a 'green' material, but certainly greener than dense concrete or plastic.

I wouldn't choose a metal stock tank for two reasons - it will conduct all the heat out of your tub very quickly - secondly, condensation on the outside of the tub would need to be captured by something underneath, and careful caulking would be needed to ensure no handy crevice exists for mold to grow.

Keep posting - I'm interested in the final solution.

This wouldn't be a quick solution but it would be an amazing experience and the end result would be gorgeous: a tadelakt

You could make it any size and shape and then waterproof finish it.

https://tadelakt.com/
https://en.wikipedia.org/wiki/Tadelakt

We used a therapy tub we found very cheap on Craigslist.  Plumbed just like a regular tub.  It's the kind you sit in and the water comes up to your chin.  Sure they must come in larger sizes than ours...

How about magnesium cement as a possibility? It's amazing stuff. It's as strong as portland cement at a much thinner application; it's waterproof; it's completely non-toxic, natural and recyclable, low embodied energy; it cures to usability in a matter of hours; it can be aggregated with organic material such as sawdust, paper pulp, you name it.
Build your form out of whatever--wood, metal, etc--then dip canvas in magnesium cement and drape it. You can drape it again for more strength or trowel on more layers, aggregated with organic material to make it thicker and smoother.
Take a look at this site for more info: https://www.greenhomebuilding.com/QandA/manufactured/magnesiumoxide.htm

I'd love to have a deep soaking tank, and other permies have posted good pictures of stock tanks that could do the trick. Old weary bones like mine would really enjoy this! Goodbye to pains of arthritis!
The main problem I see is entering and exiting such a contraption.
I'm all in favor of a tub with a narrower footprint than a conventional bathtub for the simple reason that it could use less hot water. Also, it would make better use of space inside the house.
But if you need a ladder to get in and a ladder to get out, then the footprint increases, negating the advantages. The ladder on the inside might eventually poke holes in a liner, or it could be a simple incorporated seat [good luck cleaning around that!] that a person could climb on to exit? although I think the liner is an A1 idea. Many stock tanks eventually leak, either because of poor construction or weather badly if kept outside. A taller tank might leak that much faster because the water pressure near the bottom seam would be that much higher.
This one, shaped like a shoe, might fit the bill:
https://www.aliexpress.us/item/3256801385139808.html?gatewayAdapt=glo2usa4itemAdapt&_randl_shipto=US
They do not make it anymore. could it be that a child got entrapped in it? could it be that no one volunteered to clean the gunk? [Sorry, but I'm a woman so I automatically look at the cleaning practicability.]
Some folding, really cheap ones, built like an oversized teacup can be made to look quite attractive:
https://www.aliexpress.us/item/2255800902024625.html?spm=a2g0o.detail.1000023.2.238166d13cJw6n&gatewayAdapt=glo2usa4itemAdapt&_randl_shipto=US
Do you notice, however, that they do not have an outside stepstool to get out? I would have  great difficulty to get out of such a contraption! Already, with a conventional bathtub, I've had to modify how I get out of it. For the curious, from a laying down position, I swing the far leg over the edge, then  the far arm and plunk myself on the outside mat. Then, I let the water out [water adds buoyancy to turn myself around]. So it is already quite a gymnastics trick to get out... Don't laugh: If you grow old enough, you may have to do the same!

Cécile Stelzer Johnson wrote:
The main problem I see is entering and exiting such a contraption.

I think there isn't one simple solution to this issue. I rejected the tubs with the doors because I tried getting in and out of one and there's not a lot of space to stand in to get out of the way of the swinging door, which on the model I tried, swings inward due to security under pressure physics.

However, on the plus side, the door tubs, like hot tubs, came with an integral seat. Having one's butt 8 to 10 inches off the bottom of the tub, can make a huge difference in being able to stand up. In fact in college I got a room with a family friend's father who was over 70 and the house had the old claw style high bathtub, and I had him make a sturdy wooden stool for some other purpose we needed it for, and he very quickly started using it to sit on to bathe. If you make it to fit the tub precisely, it should be possible to make it not tippy.

However, another advantage of the claw style tub is that the top edge was rolled over, thus a person could actually get a grip on the edge. Modern tubs are almost too smooth and there's nothing to grip. Grab bars in several locations are only helpful if those locations actually work! Definitely room for permies' innovation and outside the box thinking! That rolled edge has the disadvantage that it's not wide enough to sit on as an intermediate step in the exiting procedure.

I'm all in favor of a tub with a narrower footprint than a conventional bathtub for the simple reason that it could use less hot water. Also, it would make better use of space inside the house.

I have used the deep, but small, Japanese bathtubs. Less surface area helps to keep the water warmer, and having your whole body submerged easily, helped me stay warm even at cooler water or air temperatures. Wet skin cools so much faster than dry skin, that unless I've been in warm water a good long time, my skin will cool very quickly if I can't keep it covered.

In the spirit of contribution will suggest an IBC tote or a large chest style freezer.
Both have been used in this capacity.
The chest freezer has insulation, and unless I'm confused, you get into a soaking tub after you are clean, and the water is kept between uses.  
You might want to follow that practice,  but if you do the insulation could help make it viable.

If I were building from scratch I think I might stack cement blocks and finish the inside with Calcium aluminate cement, like RapidSet CementAll .
From there conventional concrete sealer should work, though I've had good luck with just CementAll.

The counter around my sink is made from   window screen stapled to lumber and parged with CementAll.
It's proven to be durable in a wet environment,  but also ugly, because I did a poor job on the finishing.

I quite agree with you, Jay on the swing in "walk in" bathtubs: The door must swing in to keep it watertight, which means you'd have to patiently wait until the tub is emptied to get out. [and they have small outlets].
I was surprised to see that the small Japanese bathtubs we were talking about are in fact quite narrow in diameter. They are only 6" wider in diameter than a 55 gallon plastic barrel such as I use for water catchment. [29"1/2 for the Japanese one and 23"1/4 for the barrel]. But the Japanese tub is only 1'10"tall which, once seated in there, I couldn't cover my shoulders. Also, seating completely in the Japanese tub may prove quite difficult to get out: [b]I'd fear getting wedged in there.[/b]
I would be tempted to place a stool for seating in the barrel and fill it enough to cover my shoulders. Plumbing and cleaning a barrel like those blue barrels isn't hard, especially if you were to use it outside and could pressure wash it every once in a while.
If kept inside, I'd feel like I would have to hide the horror of a plastic barrel with perhaps some sort of a nice wood decking built around it perhaps a nice metal grab bar to help hoist myself out? or a rope ladder?
https://www.ebay.com/itm/385391605826?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1jT_PzyBfQkitzv9WncZHDw17&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=385391605826&targetid=1584571731043&device=c&mktype=&googleloc=9019203&poi=&campaignid=15275224983&mkgroupid=131097072938&rlsatarget=pla-1584571731043&abcId=9300697&merchantid=507160669&gclid=CjwKCAiAioifBhAXEiwApzCztqu3YtsbauJ4p8tfWtMB5UauIfHjft4NIJWWUxvK7zM2IMqyx4F4IBoCWo8QAvD_BwE
That could totally work. The deck would also make it easier to get in and out of.
This site, which Jan White mentioned offers all kinds of barrels:
https://www.nationalstoragetank.com/product-category/plastic-tanks/rain-harvesting-tanks/
Some are pricey... but if we compare with bathtubs being sold for bathrooms these days, they are more than reasonable. Some are too large to save any money on water [they are more like cistern-big!] But I’m sure one could be selected to work just right.

Cécile Stelzer Johnson wrote:I would be tempted to place a stool for seating in the barrel and fill it enough to cover my shoulders. Plumbing and cleaning a barrel like those blue barrels isn't hard, especially if you were to use it outside and could pressure wash it every once in a while.
If kept inside, I'd feel like I would have to hide the horror of a plastic barrel with perhaps some sort of a nice wood decking built around it perhaps a nice metal grab bar to help hoist myself out? or a rope ladder?

I think you've got a plan, Cécile! Yes, some sort of stool would likely make it more comfortable to actually soak and relax, but you may have to build one yourself/have it built to fit.

If you position it well, you can use the outflow for watering the garden. You still need energy to heat the water, but at least the water will have a second life.

Rope ladders are *really* wiggly to use - as a senior myself, despite having decent balance, I'd consider it much safer to look at rigid options that are light enough to lift into and out of the barrel, or something rigid but collapsing like this (although the price has me thinking I'd find an alternative!)
https://www.amazon.ca/Telescoping-Lightweight-Collapsible-Retractable-Extension/dp/B08979MZ8Y/?th=1

Jay Angler wrote:

Cécile Stelzer Johnson wrote:I would be tempted to place a stool for seating in the barrel and fill it enough to cover my shoulders. Plumbing and cleaning a barrel like those blue barrels isn't hard, especially if you were to use it outside and could pressure wash it every once in a while.
If kept inside, I'd feel like I would have to hide the horror of a plastic barrel with perhaps some sort of a nice wood decking built around it perhaps a nice metal grab bar to help hoist myself out? or a rope ladder?

I think you've got a plan, Cécile! Yes, some sort of stool would likely make it more comfortable to actually soak and relax, but you may have to build one yourself/have it built to fit.

If you position it well, you can use the outflow for watering the garden. You still need energy to heat the water, but at least the water will have a second life.

Rope ladders are *really* wiggly to use - as a senior myself, despite having decent balance, I'd consider it much safer to look at rigid options that are light enough to lift into and out of the barrel, or something rigid but collapsing like this (although the price has me thinking I'd find an alternative!)
https://www.amazon.ca/Telescoping-Lightweight-Collapsible-Retractable-Extension/dp/B08979MZ8Y/?th=1

Yep, come to think of it a rigid ladder would be so much better. At 74, wiggling ladders are not for me...I'd attach it to the deck. I already have the watering barrels [6 of them] in position in the garden to pick up the grey water. They empty in the beds by gravity.
I'm pretty good at swinging a hammer, so building a three legged stool to sit on inside the tub isn't too hard. The platform to it on would be a half circle to fit inside the diameter of the tub. I think a tripod because it takes 3 points to define a plane, so it should be more stable. I might have to add some metal or the 3 legged wood stool would float . LOL.
Unless I park that solid ladder behind my back when I'm seated and fasten it to the deck? That should work: To get  out, I'd stand up, turn around and go up the seat then the ladder. That should work.
Yep, heating up the water will be trickier: It would take lots of hoses coiled on the black asphalted driveway to heat up enough water for just one soak!
Wood heat, warming up a coil of circulating water? [With a barrel full of cold water, circulate the water from the bottom of the 'tub', to a metal coil passing over the fire and keep dropping that hot water inside the tub from the top until the water is warm enough? [Essentially the same as percolating coffee] except that I have not figured how to stop the fire when the water is good and ready... safely, that is. Closing the feeding valve at the bottom of the barrel is as far as I've gone. I would still need to deal with the hot coil over a still raging fire.
Hmmm. Back to the drawing board.
I feel like I'd have to prepare the bath to the right temperature, then stop everything, then soak. [but the fire might still be hot for a long time under that near empty coil, so...]
Maybe a coil on a tripod that I can swing away from the fire... or a hot pan of firewood that would swing away or get dragged away from the coil...
It feels a bit half baked and iffy. I'm getting there but I need a better way to accomplish that.

Wouldn't this be a great application for a rocket mass heater? I seem to recall seeing a design for a dedicated water heater based on a rocket mass heater.

I would think you would need to use chemicals to keep the water hygienic, or raise the temp to pasteurisation temperature and let it cool to tolerable temperature before each use. This would be a good puzzle for the next Appropriate Technology Jamboree.

Mary Combs wrote:Wouldn't this be a great application for a rocket mass heater? I seem to recall seeing a design for a dedicated water heater based on a rocket mass heater.
I would think you would need to use chemicals to keep the water hygienic, or raise the temp to pasteurisation temperature and let it cool to tolerable temperature before each use. This would be a good puzzle for the next Appropriate Technology Jamboree.

The water from my well is hygienic enough to drink, so it is probably good for bathing. But it is ice cold.
A couple of things to keep in mind is that the pasteurization of water occurs at 140 F while humans throttle down the temperature that comes out of any fixture to 120 F maximum. I love my bath water hot, but 140F would be scalding hot and unsafe.
I do love your idea of using a rocket mass heater to heat up the water. It probably would need to be tweaked a lot because the rocket mass heater is excellent at heating air. I'm not sure how to incorporate water in the design to obtain bathwater, but making hot water from a rocket mass heater has been done. And excellent design is shown here, but it is actually too efficient
https://youtu.be/bWeydYLVZAo
But even in centigrade, it is way too hot.

Mary Combs wrote:Wouldn't this be a great application for a rocket mass heater? I seem to recall seeing a design for a dedicated water heater based on a rocket mass heater.

I believe Wheaton labs has been working on this concept and I believe I've seen designs on the web, but it does take a *lot* of energy to raise the temperature of water. I've also seen people using a claw style tub raised on blocks and a fire built underneath it. I think that would be both less efficient and much smokier than adapting an RMH.

I would think you would need to use chemicals to keep the water hygienic, or raise the temp to pasteurization temperature and let it cool to tolerable temperature before each use.

This is why it would be nice to keep the tub as small and efficient as possible. I would prefer to use the water in a green house and simply dump it every time, rather than have to treat it with chemicals myself. There are concerns about this issue if you try to use solar water heating, as things like Listeriosis which grow nicely at lower temperatures, that are particularly dangerous for seniors. However, I don't see why you can't pre-heat with solar, then get the tub up to pasteurization temperature (I'd have to research how long), then add safe cold water to bring it down to the temp you want. I don't know for sure if that would be safe enough - more research needed!

The cheap option:
Google Korean portable bathtub (or inflatable or plastic instead of portable and you'll get mostly the same hits)

For the Nice option, you can also google DIY Japanese Soaking tub and get lots of tutorials for nice wooden and molded cement options.

Its funny how as soon as you focus on a topic you start seeing related items in unexpected places.

Here is the caption that went with the picture:

"Ensuites normally don't have room for a bath, much less small ones, but there are some great new designs that are made specifically to fit into a compact space, such as Albion Bath Company's deep Tubby Torre bath shown here. "

Oh, Mary!  That "Tubby Torre" bath from Albion looks perfect!  But alas, Albion is a UK company and though you can technically "get anything"  I believe this to be out of my range.

I found a Youtube video where some folks simply built the tub, then covered it with waterproof wallboard, caulked it up and added tiles...it is doable and maybe more afffordable; and we will get exactly what we want (a deep, vertical bath on one side and a step-in shower next to it, with a half-door that slides over one function or the other, and a built-in step up that extends to provide a riser for a composting toilet)

Here's the video.  I want to thank all posters for taking the time to help me figure this out!!  

https://www.youtube.com/watch?v=8QE-nZR_tek

Albion just happened to be what popped onto my screen while looking at some other self-build projects.

There are American alternatives - https://www.thetubconnection.com/made-usa.html

Custom build is a 'once and for all' proposition, where as installing something free standing saves a lot of time and future proofs with flexibility and the chance of reselling it, if plans or lifestyles change later. At least the Albion products might have prompted some ideas. Good luck with the project!