Amy Bell

I am just about to finish construction of my RMH and I am trying to look into the best option for plastering. (Best being easiest to do with easy to find supplies.) It is in my greenhouse so it will need to resist moisture fairly well.
Also, I'm assuming that everything is going to have to be very dry prior to being plastered....so it may be a while before I can do that part. This is my first RMH and I've never mixed a plaster before.

You guys are awesome with all the info. On the box transition area, my husband can’t pass up a chance to work with metal so his is currently building me one...while I pleasantly hurry him along. 😂
But I have another question because I’m finding sooo many different answers. What mix of cob is best for the bench area? I’m using rocks in it as well but I need to know the best cob mix to surround everything.
I seriously appreciate all of y’all’s experience and willingness to lend a hand!!!

Thank you so much! That was incredibly helpful! I will absolutely take your advice on this. I will switch to the 8" system and will definitely build the clean out box. I put in the 'cob' base a few days ago and I am hoping to begin the building process today.

Thomas, thank you so much. Hey the stove pipe and ceramic fiber blanket  sounds like a great idea for me! But let me make sure I'm not misunderstanding. You said fit the ceramic blanket inside of the stovepipe for the riser? would that mean that I need to go up a size in the stove pipe? I apologize for all the questions but I sure appreciate all the help!!!

another quick question.... if I cast the riser from 'fireclay' and perlite, what are the ratios for making that? The only clay I have worked with on the farm, has been the dirt! Great for cob!

Thank you so much for the welcome!

My greenhouse is 20x25. I do use it year round, however, it is mostly for seed starting. We don't have horrible winters here, but we do tend to have crazy freezes in the early part of the year. Last year I lost a bunch of my seedlings and I don't want that to happen again. I just need to keep it above freezing at those times. My plan was to build a 6" J tube and use the warming bench for my seeds that like to sit on a heating pad. LOL. I've honestly even thought about just doing a small wood burning stove surrounded by bricks, etc for thermal mass, no more than I'm actually gonna need to use it. However, I do have a large hoop house as well and will be building another and would love to plan for larger RMH systems for those.
I ordered the plans for the 6" system so that I could have a close look but I honestly think I'm even more confused now!?!? Maybe I need a nap!

I have been searching through all of the wonderful information here and I believe my head is now spinning. I am trying to gather everything to build a RMH in my greenhouse....right away. I've seen so many different options and designs.
Question 1. My greenhouse is wood/glass but dirt floors. We are VERY much clay in this area. I am wondering what the base needs to be.. I mean, do I need to put in a slab? or could I build it on the ground? I understand the design portion (I believe) but I obviously need to figure out the foundation before I begin.

Question 2. Is a steel pipe ok for the burn tunnel? or should it be fire bricks?

Thank you in advance for any assistance...