Masonry Rocket Mass Heater. My first build

Hi everyone,

This is going to be my first build which is on a 4" slab in my office/studio/classroom
I will be using the space for teaching workshops (it's a newly renovated space which was a very very run down workshop).
My goals are to create an efficient wood heater that is STUNNING. There is no wiggle room for anything else other than perfection.
This build is for me to iron out any issues before I build another in our living room on a 6' high suspended wood floor but also
(as mentioned I teach workshops) this will probably be the very first RMH (or any kind of mass heater) the visitors have seen.
It's vital to me that they want to have one and not be put off by the look. That means no barrel or at least no visible barrel.
It means straight lines built from brick and either a rock fascia or a clay plaster.

I'm going to be using
Matt Walkers Brick Rocket Mass Heater Plan

There are some pictures in the link above from another build.
I have also attached a crappy sketch of how I will be building mine. It may also get flipped horizontally. It just depends how much clearance
a brick bell requires on the wall side (the backside)
I don't want it to protrude out into the doorway on the far left.
Thanks all for your help. This build will commence in February once I'm back from my Christmas holiday

Hi Dan;

A nice 1/4" thick copper plate around your feed tube ,would look great and at 1/4" it will not effect your feed tube height.  Granite would work fine and look great for the other flat surfaces.

If the copper plate isn't quite right for your design.  Leaving your granite back 1 to 1.5 " back from the edge of the fire brick will certainly help protect it from the heat.  Gerry suggested possibly using ceramic fiber board   (1/2") under your granite that is over the feed tube. This would work fine as well. I would still keep the granite away from the edge.  
I tested the temps on my stove last night.  The top of the fire bricks were 225-250 F if I measured down 2" temp was 570 F +  

thomas rubino wrote:If the copper plate isn't quite right for your design.  Leaving your granite back 1 to 1.5 " back from the edge of the fire brick will certainly help protect it from the heat.  Gerry suggested possibly using ceramic fiber board   (1/2") under your granite that is over the feed tube. This would work fine as well. I would still keep the granite away from the edge.  
I tested the temps on my stove last night.  The top of the fire bricks were 225-250 F if I measured down 2" temp was 570 F +  

Thanks Thomas,

If the granite was pulled back from the edge 1-1.5", would this be accounted for the feed tube height or not, please?
Realistically the granite that is cheaply and widely available from kitchen remodelling is only 1.25" thick. 2" is much more expensive and not used so much these days here.
What I could also do is make a few sacrificial rectangular pieces of the granite and mortar them in place (or a soapstone trim around the feed tube of just a few inches). If they crack I could simply replace them.
I want to use a dark material on the top to contrast the light clay plaster but also so dirt, ash, soot etc. does not stain and mess up the top.
This is something I see in a lot of RMH photos/videos and I believe it's another off-putting feature of the RMH (for a lot of people) as it is with any other wood heaters too.

So you know, I have bought the RMH builders guide and Ianto's original book. I also helped crowdfund all of Pauls DVDs on rockety things and also E&Es other DVD
so I have all that information. I have also created a notepad of all of the RMH (main topic) podcasts so I have those on a separate playlist from the other Permies podcasts.
I'm hoping any questions I have are mostly outside of these resources.

Thanks for all your help, it is greatly appreciated
Dan

Dan
I would say that your granite at 1.25 tall and 1.5" back from the edge of the feed tube, you would be safe as far as not altering your feed tube height.

I do like your thought's about using smaller sacrificial pieces of granite or soapstone if you need too.

For your application, of a showpiece rmh that folks can sit on . I would consider using the Walker style 1/2 barrel's in your bench. They would heat up your bench faster than a traditional  pipe thru mass method.

thomas rubino wrote:
For your application, of a showpiece rmh that folks can sit on . I would consider using the Walker style 1/2 barrel's in your bench. They would heat up your bench faster than a traditional  pipe thru mass method.

Thanks Thomas,

Matt's plan is a brick bench bell with no pipe.

Thanks
Dan

Hi All,
I have been very busy over the last couple of months building my RMH.
One of my biggest hurdles getting started has been too many opinions and ideas.
For that reason, I chose not to put anything on permies until I was completed.
It wasn't to be rude (as all the comments from others can be very helpful)
but it was so I could just stay on track with one design and if I'd made a thread I would be tearing my hair out with all the different ideas and opinions.
The only person I got feedback and help from was Matt Walker who designed the base plan.
I did modify the plan somewhat but I didn't mess with the core.
It went very well with no issues what so ever.
After listening to Erica and Ernie over the years saying stick to a plan...I did just that.
Naturally, I wanted to do a million upgrades but I held steady and stuck to the plans.
By the way, the changes I made were all ran past Matt before I did them.
I filmed a lot of the build which I'm editing into a feature film ;) right now.
It's about an hour-long of the majority of the build.
I should have that finished next week some time.
The rough edit is done. I'm just polishing it now.
I also have a timelapse of the whole build which I can post later today.
I ripped my bell down halfway through the build and rebuilt it almost twice the height and double bricked the wall next to the bench.
I liked the idea of leaning up against the heater and found it was too too hot (like 90c).

Hey Dan! Havn't had time yet to watch your videos but just wanted to say a big whoooohoooo to you!

Hi Dan!
 I have't watch video or read details yet- looking forward to it.
The end product looks Awesome!!
Very "low profile" for a rmh!! Mine seems like a sloppy goliath in contrast. (earnestly working on plaster this weeked!)

Are you please with performance?
Staci

Staci Kopcha wrote:Hi Dan!
 I have't watch video or read details yet- looking forward to it.
The end product looks Awesome!!
Very "low profile" for a rmh!! Mine seems like a sloppy goliath in contrast. (earnestly working on plaster this weeked!)

Are you please with performance?
Staci

Hi Staci,
I was trying to get the modern look.
I’m still learning and my crappy brickwork made the plaster coat much harder.
Next time, I will get the brickwork perfect before plastering.

I was also trying to avoid the “giant toilet” look that, once you mentioned, I’d very hard to un-see 😐

It’s a good little heater.
It’s only about 2 tonne but does the job.

I built it in mind to moderate the temperatures in a lightweight structure.

It does not release heat quickly like a barrel but
We do not get super low temps here so it’s not such an issue.

Dan