Help to build RMH in Western Australia

thomas rubino wrote:Hi Madeleine;
Finding a competent person to build you an RMH in Australia could be hard.
It's just not cold enough to have hundreds of builds in the neighborhood.
The right handyman, if you can find one, would be able to build one.
Once you understand how they work, I promise that YOU will be able to build one all by yourself.

If you are reading the Wisners book, then you are learning all about J-Tube RMHs.
They are the first design and the easiest to build...
They utilize a piped mass with rock and cob as their mass (a lot of work)
That method has been updated since your book was printed.
Most new builds now use a hollow bell (box) to store your heat.
The hottest air rises to the top and the cooler air sinks, your chimney inlet is placed near the floor of the bell.

All you need are bricks for your J-Tube core, the bell itself can be built with concrete blocks if they are easily available or large stones sealed by cob.
You will need clay and sand.    Your clay can be local but it is easiest to purchase a sack of dry powdered clay from a pottery shop.

I know it all seems so very complex that you feel overwhelmed by the build.
I assure you it is not and that indeed you can build this all by yourself, with some guidance from our staff.
Many independent women and men have successfully built their RMH all by themselves!
I assure you they are extremely proud of their accomplishment and full of confidence to share their knowledge.
This can be your story as well...

thomas rubino wrote:Matt Walker may have built the first "bell" system using an 8" J-Tube RMH splitting several 55-gallon barrels lengthwise and using them to bridge over low side walls. He then cobbed over the barrels creating a heated bench with no pipes.

thomas rubino wrote:Hi Madeline;
Reading through some of the posts here at Permies will help.
Then there is Peter Berg's website, https://batchrocket.eu/en/
Peter developed the batchbox design and his builds all use a bell system.
You will find a detailed technical description of bells on Peter's website
Matt Walker may have built the first "bell" system using an 8" J-Tube RMH splitting several 55-gallon barrels lengthwise and using them to bridge over low side walls.
He then cobbed over the barrels creating a heated bench with no pipes.

Madeleine Innocent wrote:

thomas rubino wrote:Hi Madeline;
Reading through some of the posts here at Permies will help.
.

There is so much info, I find it a bit daunting!

thomas rubino wrote:Hi Madeline;
Apologies for my ignorance of how cold it can get in Australia.
I had no idea!  
Yes, Peter's site has a vast amount information.
It is easy to feel overwhelmed.
I sent you to Peter's site to learn about bells and what size they should be.
Building a batchbox design RMH is more technical than a stock J-Tube.
I suggest you start with an 8" J-Tube and run the hot air into a bell rather than a piped mass.
Later you can always upgrade to a batchbox design if they interest you.

We commonly suggest you practice building a J-Tube in your yard.
No barrel just the core RMH with a riser.   This is a fun thing to do and you will gain confidence in how to assemble the core.

Have you checked into building supplies yet?
Are firebricks available?  Dry bagged clay?  Regular solid clay bricks?
Does your home have a chimney?  What size is it if you do?

Madeleine Innocent wrote:

thomas rubino wrote:Hi Madeline;
Apologies for my ignorance of how cold it can get in Australia.
I had no idea!  
Yes, Peter's site has a vast amount information.
It is easy to feel overwhelmed.
I sent you to Peter's site to learn about bells and what size they should be.
Building a batchbox design RMH is more technical than a stock J-Tube.
I suggest you start with an 8" J-Tube and run the hot air into a bell rather than a piped mass.
Later you can always upgrade to a batchbox design if they interest you.

We commonly suggest you practice building a J-Tube in your yard.
No barrel just the core RMH with a riser.   This is a fun thing to do and you will gain confidence in how to assemble the core.

Have you checked into building supplies yet?
Are firebricks available?  Dry bagged clay?  Regular solid clay bricks?
Does your home have a chimney?  What size is it if you do?

Building supplies are no problem. I have a lot of used bricks that I could clean and use. I already have a wood burning stove and flue. So I just need to adapt it. As far as I can see, the flue is unlined. That seems normal here as the chimney sweep has never commented on that, and he comments plenty! The house is single story and the flue comes out below the top ridge but the top is higher. It's capped. It draws quite well when it's not clogged up with creosote! The diameter is 13cm/5 inches.

The southern parts of Australia are often blasted by the freezing Antarctic winds.

I appreciate your imput.

thomas rubino wrote:Well, once we help you build your RMH, creosote will no longer be an issue at all.
There will be no reason for the chimney sweep to complain or (unless it is mandatory) even visit at all!

You call your chimney a flue.  Is that a block chimney? Or a metal pipe?
At 13 cm it is smaller than normal for a 6" J-Tube.
But as it draws well (when not plugged) it should work fine.

I never asked about a barrel.  
You will want a 55-gallon barrel preferably one with a removable lid.

What kind of bricks do you have?  
Are they clay?  Are they solid or do they have holes in them?
Are there any fire bricks / Kiln bricks?
You are going to want a hundred or more.

Were you wanting a heated bench to sit on or would a heated rectangular masonry structure better fit your space?

thomas rubino wrote:Well, once we help you build your RMH, creosote will no longer be an issue at all.
There will be no reason for the chimney sweep to complain or (unless it is mandatory) even visit at all!

You call your chimney a flue.  Is that a block chimney? Or a metal pipe?
At 13 cm it is smaller than normal for a 6" J-Tube.
But as it draws well (when not plugged) it should work fine.

I never asked about a barrel.  
You will want a 55-gallon barrel preferably one with a removable lid.

What kind of bricks do you have?  
Are they clay?  Are they solid or do they have holes in them?
Are there any fire bricks / Kiln bricks?
You are going to want a hundred or more.

Were you wanting a heated bench to sit on or would a heated rectangular masonry structure better fit your space?

thomas rubino wrote:Hi Madaline;
I have forgotten to ask, what is the floor of your house made from?
Concrete slab?
Wood floor with joists? Is there a crawl space or a basement?

So think about your space and then imagine it with a long couch-like bench... will it fit?
Yes, cats dearly love all wood stoves (the kitty warmer) but love RMHs in particular.

Now think if a masonry structure might fit the space better.
Bells can be almost any shape, tall and thin, rectangular, square, or low with raised portions.
I have been talking about using bricks for your bell, but they can be made out of metal as well.

Have you looked into the cost and availability of firebricks?
Here new firebricks cost around $2.40 a brick
You do not want the thin(split) bricks, the full-thickness bricks hold up much better.

thomas rubino wrote:Hi Madaline;
Great news you have a solid concrete floor!
You will need to protect it from heat under the core.
The easiest way is to use a frame filled with 3.5" of perlite/clay.
Another option would be to raise the core and mass leaving an air gap underneath.

Your question about bells versus a solid mass is very valid and to my knowledge has not been proven one way or the other.
I have both.  Our studio dragon started life as an 8" J-Tube with a solid piped mass. That stove was later converted to a 6" batchbox design but I retained the 8" piped mass. This stove is a fire-breathing dragon, it works great and holds heat for a long time.
My shop stove is of the bell design.
It also is a  fire-breathing dragon that works great and holds heat for a long time.  

Almost all new builds are using a bell design.
The consensus seems to be they work just as well as a piped mass but are easier to build and do not need their mass pipes cleaned each season.
Good enough reasons for me.

Now let's talk about your design.
You have chosen a bench. One thing I will mention is, that I recommend that your RMH be spaced a few inches away from your outside wall.
We want the heat to radiate into the room and not transfer through the wall to the outdoors.
This also allows your blanket or covering to hang properly rather than sliding off.

A beautiful RMH in your photo.  It is using all cob.  Nothing wrong with that other than the work creating and the upkeep of the outside.
Cob is easy to break/ gouge or be scratched and will need maintenance. Not a big deal but...
I suggest a retaining wall of brick make up the lower portion of your bell.  This will allow you much more freedom of cob consistency.

It is your choice of bell or pipes. Using a brick retaining wall works for either method.
If you choose a piped mass, you will want as many large stones as you can, to make up the bulk of your mass.

The cob is used as a filler over your pipes and surrounds each stone leaving no air gaps.

I've included a couple pictures from our studio dragons early days.

Madeleine Innocent wrote:

thomas rubino wrote:Hi Madaline;
Great news you have a solid concrete floor!
You will need to protect it from heat under the core.
The easiest way is to use a frame filled with 3.5" of perlite/clay.
Another option would be to raise the core and mass leaving an air gap underneath.

Your question about bells versus a solid mass is very valid and to my knowledge has not been proven one way or the other.
I have both.  Our studio dragon started life as an 8" J-Tube with a solid piped mass. That stove was later converted to a 6" batchbox design but I retained the 8" piped mass. This stove is a fire-breathing dragon, it works great and holds heat for a long time.
My shop stove is of the bell design.
It also is a  fire-breathing dragon that works great and holds heat for a long time.  

Almost all new builds are using a bell design.
The consensus seems to be they work just as well as a piped mass but are easier to build and do not need their mass pipes cleaned each season.
Good enough reasons for me.

Now let's talk about your design.
You have chosen a bench. One thing I will mention is, that I recommend that your RMH be spaced a few inches away from your outside wall.
We want the heat to radiate into the room and not transfer through the wall to the outdoors.
This also allows your blanket or covering to hang properly rather than sliding off.

A beautiful RMH in your photo.  It is using all cob.  Nothing wrong with that other than the work creating and the upkeep of the outside.
Cob is easy to break/ gouge or be scratched and will need maintenance. Not a big deal but...
I suggest a retaining wall of brick make up the lower portion of your bell.  This will allow you much more freedom of cob consistency.

It is your choice of bell or pipes. Using a brick retaining wall works for either method.
If you choose a piped mass, you will want as many large stones as you can, to make up the bulk of your mass.

The cob is used as a filler over your pipes and surrounds each stone leaving no air gaps.

I've included a couple pictures from our studio dragons early days.

I totally agree. I'm still exploring and hadn't realised all the differences. Less work works for me, so you have convinced me to build a bell. You've just reduced my overwhelm considerably.

thomas rubino wrote:Hi Madeline;
So, you like cold Montana stories...
This Friday, Jan 12th we are expecting a low of -30C and a daytime high of -17C...
For five days or so we expect severe below zero F temps, and then after that, it will warm up and snow.
Certainly not this winter (so far) but some years we can get 4'-5' here in the yard.
We are 2600' above sea level.

A new choice you need to decide on is how you want to cover (roof)  your bell.
Some folks like large flagstones, while others use fancy granite countertop material.
You could use a corrugated metal roof sheet properly supported underneath and then cover it in cob.
Another option is to use 55 barrels, split lengthwise.  (Matt Walker style)
These would sit inside on a ledge in your brick surround and be covered by cob.  
Other than cutting the barrels, this is easy and very strong.

Madeleine Innocent wrote:

thomas rubino wrote:Hi Madeline;

OMG I can't even begin to imagine. And I thought I was crazy living here...

Matt has three sets of plans for RMH and none of them mention the bell type. He doesn't seem to take emails to ask.
Cob looks nice but seems a lot of work, both initially and maintenance. Bricks seem to be less work.

Scott Weinberg wrote:

Madeleine Innocent wrote:

thomas rubino wrote:Hi Madeline;

OMG I can't even begin to imagine. And I thought I was crazy living here...

Matt has three sets of plans for RMH and none of them mention the bell type. He doesn't seem to take emails to ask.
Cob looks nice but seems a lot of work, both initially and maintenance. Bricks seem to be less work.

I am not sure any self built stove will not be a lot of work. They simply are, I would rather choose to think of"what I end up with"  My bell is 4' wide 5.5' deep and just about 7' high    I have not got the official count on bricks yet, but they were all carried into the house, 4 at a time, for 60 feet,  All the mortar, doors, and T bars.  Everything by one person. Me.   Not in a day, not in a month, but from 1st of June to Nov 4th.   Everyday with something done.

Rome was not built in a day or month or year.

If I had to pay for labor, the guess would be they would charge 1/3 of years wages to a brick layerr Which doesn't make sense for someone to do what anyone in the future will be carrying fire wood could do, that is simply, carry in and set bricks into a preplanned pattern with known results waiting. Speaking of labor,  Your time spent on the build, will be rewarded for YEARS to come in labor saved for cutting/splitting wood, using less than 1/2 for the same amount of heat.  I do not fall into the "saving 90% of the wood needed" club.  But 50% off is a realistic goal

There are some tricks, but that is what your here reading the forum to find.  Toss in the cost of a diamond wet saw, (technically it will be free due to time savings, i.e. labor) and you will have it forever or you can sell it.  The rest of the items are cheap, trowel, string line, level.  Any metal work, with plans in hand, should be able to be carried out and have it fit,  1st time out of the gate, so that is not a deterrent.

If you pick up on what I am saying, a plan, no matter what it is, helps greatly.

I absolutely love what the experimenters have been doing, but let them prove what works and what don't.  There is no reason for us builders, for us to be in the experimenter ranks with known working models and dimensions out there.  Yes, I have been on that stump a long time, but it is important.

Best of success.

thomas rubino wrote:Hi  Madeline;
Yes, any brick can crack under extreme temperatures.
However, it takes a lot to get a firebrick to crack, and most times cracking is all it does, the brick does not disintegrate, it simply has a crack across the face.
Automotive high-heat exhaust repair goop will repair a cracked firebrick for years.
I suspect your chimney guy is used to firebricks used in open fireplaces, where people toss wood into the fire, bouncing it of the bricks. The same is true with wood-burning box stoves, people throw in the wood not caring that it bounces off the sides.
Also, there is a big quality difference between firebrick used in a box stove over industrial firebrick intended to be heated to 1800-2000F.
Any firebrick purchased should be rated to 2500F or more.

Madeleine Innocent wrote:I had my chimney sweep come before the winter starts - . He is an old school sort of guy and not too interested in 'new fangled' ideas, so I wasn't going to mention RMHs. But somehow I did. He mentioned that there is a problem with fire bricks, wherever they come from. They tend to crack. Has anyone experienced that?

In addition, he mentioned that more people are going for wood burners as electricity has gone up so much. There's going to be a problem accessing enough wood as the powers-that-be have, finally, protected all old growth forests from even collecting fallen wood.

Seems to me an ideal market for someone to learn and build RMHs here.