Tiny house rmh

I have a tiny house that is a converted shed set on concrete blocks. The floor is plywood and that is supported by 4x6” beams on 4’ centers. Access under the floor is possible to beef up the support. The house is insulated on the walls and ceiling. At 12’ wide by 20’ long with an 8’ ceiling height, which design is suitable? There is about 4-6’ of horizontal wallspace, run available for the entire unit.

I am a complete novice, so I ask for forgiveness in advance, for being unfamiliar with the terminology.

Thank you.
Skash

Hi Skash;
Welcome to Permies!    And welcome to the wonderful world of Rocket Science!

12' 4x6 on 4' centers is already stout.  At the most  a little extra under the RMH itself  might be helpful.
That is not a very large area and you have it insulated.
If it fits your style I would suggest a J tube rather than a batchbox.
I think a 6" would be large enough but myself I would build an 8".
Rather than a plain metal barrel, I would  surround a barrel with bricks or build a brick bell to avoid  overheating.
A brick or metal bell  to fit the rest of the space.

Many thanks for the warm reception.

May I ask which J tube plan would be suitable for my needs? The lowest temperature last year was in the mid-teens.

I need to build it as inexpensively as I can. I am retired on a low, fixed income through social security.

One concern is weight distribution since my house is on concrete block piers. I fear settling/sinking under the heater. I imagine a support structure that distributes the weight over a larger footprint.

If there is also a way to cook with it, an oven basically (indoor or outdoor to save interior space) that would be very helpful.

It’s good to have a direction. Now I just have to refine it so I can begin gathering the materials and prepare to build it.

Hey Skash;
A quick answer, is a 6" J tube would be large enough to easily heat your space.
In my previous post , I said I would build an 8" simply for the larger feed tube, larger wood and length of burn time.

When you ask about "plans".  
For your application, only the J tube dimensions and transition area are important to follow closely.
We will happily tell you those dimension's.
Your space requires a custom fit bell rather than a piped mass.
Absolutely,  add extra  support directly to the ground  if you are concerned about settling.

Can you cook on a J tube?
Well, yes easily for stovetop cooking.
But an oven might be a project.
I have heard of insulated metal boxes set on or over the barrel.
I do not know how easy it would be with one to maintain oven temps without burning or undercooking.
I am currently building an outdoor rocket powered black or white oven.
It could be modified to be an indoor heater /oven.
Many clay bricks are needed to build one.

As far as materials to gather.
A few things are  best bought .
Fireclay in #50 sack.   At the right location these run as low as $7 - $15
Firebricks can be found used, but also cost less than $2 each at a masonry supply  (same place you buy fireclay)
Sand is free  although I buy #100 sack of builder sand at Home D for the consistency of size with no rocks.
Depending on how much cob you need will determine how much sand you want to gather.
The mix is three part sand to one part clay, so in some cases a dump truck load is not to much.

Clay bricks are your best friend if available used free...  then bring them home  as quick as you can.
Or new clay bricks are .48 each at home D.