I am doing research on building my own backyard tub. I've spent countless hours on the web trying to piece it all together because I am planning a slightly unconventional build. I'm aiming to use brick on a concrete base. I know my way around bricklaying and have a cheap supply of stone and concrete so it seems a logical choice.
So far I've come up with the design below. I am planning a concrete slab, a 3'5ft high round wall out of brick with a square firebox in direct contact with the water. There will be a small hatch to feed the fire on the outside. I will run a 1" stainless spiral tube through the firebox so I should get dual heat transfer, by radiation of the brick from the firebox as well as the hot water running through the tube.
I'm wondering if there is anyone that can comment on this design from personal experience. There is a ton of info on wooden tubs out there, but not so much on brick ones. Questions I'm still fighting with are:
- Why is stone not used more often in hut tub builds?
- Do I need to insulate the bottom and walls? This would add a significant amount of effort to the build
- What to expect from the heating, would this setup work well for a 6ft diameter tub?
- Should I make the benches hollow so the hot gasses from the fire can travel underneath and heat the benches as well?
Any advise, thoughts or questions are highly appreciated!
