Rocket Mass Heater Project for the Greenhouse
Video at the Bottom
Last year, we had a sneak attack late freeze that killed a bunch of my seedlings and I decided at that time that I was going to fix that problem and the rocket mass heater would be the best option.
I’ve studied for years on various natural building methods and I loved the idea of the rocket mass heater. I had just never seen one in person. I did a great deal more research, trying to get as much information as possible so that I could design it properly. I needed my design to, not only fit nicely into my greenhouse, but also to work efficiently and utilize what I have on hand.
Prep Work for the Foundation
I knew where the RMH would sit so I had to prep that area before construction could begin. I did use that corner for my click brooding area, so that had to go and we had to make way for the size and weight of the heater.
One of the things we did to prepare was to put up some metal roofing against the walls where the heater would be. For one, it acts as a barrier, protecting the wood but also helps to reflect the heat back into the room. We also dug out any loose dirt and vegetation that was in the way and tried to level it out as best we could.
Constructing the Foundation
The first layer that I put down was a few inches of pea gravel that we had left over from our Natural Pool Build. Our greenhouse has a dirt floor and when we get super hard and heavy rains, we sometimes get water in the particular corner. The gravel assists with drainage.
The next layers were solid clay, having soaked in water, and heavy layers of straw…back and forth–multiple layers. As I layered them in, I stomped around in all of it with my muck boots, acting as a human mixer! Lots of work, but it honestly wasn’t that bad.
When all of the layers were in and very well mixed up, we tamped it all, using a cast iron tamper and then we smoothed it all out with a trowel. The foundation ended up being about four inches thick ….and very strong!
Finishing the Foundation
It took a little over a day to get this ready. That includes cleaning the area out, digging up clay, prepping the ground, layering the gravel, clay and straw, cob-stomping to mix it, tamping and troweling. What seemed like it might be a daunting task in the beginning, really wasn’t that big of a deal at all. I was extremely pleased with how it turned out and quickly it went it. I ended up giving it a couple of days to solidify enough to begin the construction of the rocket mass heater. That is on part 2 of this project. You do not want to miss that!!!
Be Sure to Check Out Part 2 of the Rocket Mass Heater Build!
The video above is a compilation of the process adding a little more to what I have here. I hope you enjoy and, as always, I welcome all questions and comments. If you take a minute to subscribe to Two Oaks Farm Talk and Two Oaks Farmstead Youtube Channel, you will never miss any of the terrific content! You will even find a bonus, because that is where we collide with A Life on the Farm.
