How much does it cost to build an RMH

I am in the process of removing our old original RMH (The Studio Dragon) to upgrade to a new double bell 6" first-generation Batchbox.
https://permies.com/t/280588/RMH#2962395
The other evening, Liz asked me how much I was spending on this new build.
Of course, I had no solid answer as I rarely pay attention to costs when I want something... (typical guy!)
After a few minutes, I told her that maybe around $1000?
Maybe... she says... don't you think people might want to know what they are getting into?
I cheerfully explained that new Blaze King stoves start around $3500 and go up over $5000!
I received the "look," as she says, I did not ask what a new, ready-made stove costs.
I asked what a person can expect their new home-built RMH to cost.

So, the best I can do is give the apx material costs on my current build.
My time spent traveling and the fuel costs are not factored in, nor will my time spent creating our new Studio Dragon be.
Prices of materials will vary depending on your location.
Availability of materials may require road trips to purchase heavy items.
Access to a pickup truck and trailer can expedite the process, but you can also make multiple trips in a small vehicle (Subaru)  if that is all you have.

I will have 950 new solid clay bricks @ .73 each, $700
I have 80 brand-new firebricks @ 2.45 each, $200
I also have another 50-80 used firebricks that were free.
I expect to use 3-4 #50 sacks of Lincoln 60 fireclay at $8 each, $30
I currently have six #100 sacks of graded sand @ $18 each, but I expect to need more, $130
I need 40' of 1.5 x 1.5 x 3/16" angle iron. I will not use 40', but it comes in 20' lengths, $100
I have a full roll of Morgan Superwool insulation( #8 density 1" thick)  $200
No costs listed for the exit chimney, as each build is different.
No costs are listed for the Batchbox core, as the entire core is being transferred from the old piped mass to the new double bell.
The approximate cost of a core with secondary tube, RA253 riser tube, and door can be $400-$700 or more.

Here is a link to Glenn's build information for comparison.
https://permies.com/t/248275/Batch-Rocket-Double-Skin-Bell

So, for a 6" batchbox with a brick double skin bell, I have spent apx. $1400 on materials.  
Only 40% off from my guestimate the other evening...  (again, typical guy)

How much will you spend?
It depends on your location and your ability to search for supplies.
It also depends on how nice you want your Dragon to look.
These prices are for all new material to create a work of art.
Much less could be spent by locating used supplies and building a utilitarian heater.

So, $1600-2500 is a fair guess for most folks to purchase materials.
Expect three to four months to acquire all the materials and build your Dragon.
Burning wood once or twice a day, perhaps a cord or two, will provide gentle warmth throughout your house during the winter season.

As we say at Dragontech, "Once you go brick, you will never go back!"

Thank you for laying this information out in such detail.
I'll make sure to keep taps on the material cost of my next build and can share it here too.

thomas rubino wrote:I have 80 brand-new firebricks @ 2.45 each, $200
I also have another 50-80 used firebricks that were free.

Are there drawbacks to used firebricks besides aesthetics? Designs where the tolerances would be needed such that chipping around the edges could make too large of a gap?

For anyone reading this that want's to get an idea of how much a RMH is going to cost, here is some further reading:
Ericas thread from 2014

Being able to incorporate second hand material and sourcing materials for (almost) free is definitely an upside in RMHs in general for me.

You would not want to use edge-chipped firebricks in the core or riser.
Away from direct flame contact, used firebrick is perfect for the inner skin of the bell.

thomas rubino wrote:You would not want to use edge-chipped firebricks in the core or riser.
Away from direct flame contact, used firebrick is perfect for the inner skin of the bell.

Being the proud new owner of a pallet of recycled firebricks, I'm wondering what specifically I need to watch out for with using them. What first occurred to me was aerodynamic drag (or is it turbulence/flow disturbance at the wrong point?). An irregular surface in the firebox will lower the limit for velocity of air flow and muffle the beast's roar. Can fire clay or refractory mortar be used to fill in those edge gaps?

Are there other reasons?

Hey coydon.
The main reason that come to my mind would be ease of use. In the core I usually only use clay slip, no mortar. So the bricks need to be a good fit.
In a BBR some of the builders only use a tension frame, so no “glue” at all. That only works with regularly shaped bricks.


I don’t think it makes a difference when it comes to the flow of the gases. And in any case, we want turbulence in the core for a complete combustion.
Time, temperature, turbulence.

Sweet score!  
Are they heavy, dense bricks? Or are they light, insulated brick?

You want your very best-looking bricks in the riser.
Next best on the lower side walls of the core (batchbox).
Your roof is best as a cast slab or custom-cut firebricks in a rafter design.
In the core, you can use fireclay mortar to smooth rough edges, but you will be reapplying it once a week or so (not a big deal)

You can also use a paint-on ceramic coating (ITC-100 HT) to speed flow and seal the brick.
But rough edges are not going to slow your dragon.
If she is a J-Tube, then she will roar. A Batchbox produces vast amounts of heat, but not a lot of roar.

thomas rubino wrote:Sweet score!  
Are they heavy, dense bricks? Or are they light, insulated brick?

You want your very best-looking bricks in the riser.
Next best on the lower side walls of the core (batchbox).
Your roof is best as a cast slab or custom-cut firebricks in a rafter design.
In the core, you can use fireclay mortar to smooth rough edges, but you will be reapplying it once a week or so (not a big deal)

You can also use a paint-on ceramic coating (ITC-100 HT) to speed flow and seal the brick.
But rough edges are not going to slow your dragon.
If she is a J-Tube, then she will roar. A Batchbox produces vast amounts of heat, but not a lot of roar.

They are dense. Taken from a kiln at the Kohler Company where they used to fire their porcelain fixtures I gather. I'm curious if this could have been an original structure from the 19th century. The bricks are the standard 9x4.5x2.5, but many have manufacturer names stamped in like I've only ever seen on old pavers.

I'm still not understanding what problem is caused by the edges. The bricks have solid sides and fit together as well as new ones over almost the entire surface. I can see where a couple bad edges connecting could cause a leak in the riser (maybe a good incentive to make an octagon riser where the bricks need to be cut anyway). Wouldn't be a problem in the firebox where there is insulative material on the other side of the brick, right? Smoothing edges in the core with clay weekly would be a big deal in my book, but sounds like it wouldn't affect performance either way?

Hey Coydon;
Those are industrial grade bricks; they probably have a 3000°F rating.
With a new cost of $5-$8 per brick they are the most durable bricks for RMH construction.
All industrial-grade items have a name cast in them; mine are all stamped 'Diablo', I believe Glenn used "Jet" brand.
Without pictures, only you know the condition of your bricks. If they are good enough, then use them.
Cracks between bricks with Superwool behind will still deteriorate if the flame can reach the crack.
As you have H.D. bricks, this will take time, but it will eventually eat through.
If you build this with clay and not refractory materials, then if you encounter degradation issues, a teardown and rebuild can be done quickly.