Dick Winters

We are trying to figure out some sort of fiber material to use, that is a good idea I forgot how important the fiber can be. And thank you for letting me know about the cracks that makes me feel a lot better about them I thought we were doing something completely wrong! We’ve put so much work into it I would hate to see it crack to pieces. It has been lots of fun playing with the mud though. Thanks for the help!

So I may have been a bit dramatic with the weather timeline. I think we still have a few weeks until we hit freezing temperatures. It has been rainy with 50-55 degrees F.

Eloise, I wish I would have checked back earlier we could not find ceramic blanket anywhere. We already have our heater built and we are currently firing it and filling the mass. We did find plenty of fire brick thick and thin at a masonry place in Wasilla.

We did go back and re-do our base layer with a sand perlite mix ( about 2.5 inches)on top of the cement board and then added and additional layer of the thick firebrick below the entire combustion unit. We used mineral wool for the riser/box insulation. After a few more firings we will take off the barrel and see how everything is holding up. So far everything is working great and we are having a blast building the fire and enjoying heat for the first time in our new home. We are still working on getting the “cob” mixture correct because it keeps cracking. We have tried more clay, more sand, and better mixing but it seems to crack regardless. But it has been a joy to build with mud and rock. Thanks again to everyone for your help and suggestions. This is a great community 🙏🏻

I have contacted Thomas Rubino via e-mail to see if he can ship to Alaska and how long/expensive it would be to get here. Home Depot does have mineral wool it looks like but no ceramic insulation unfortunately I have called all locations of Lowes as well. Winter will be here shortly so we do not have too much time to wait for shipping etc otherwise I would just order it. I’d say we have about 3 weeks maybe 4 to get this built before temperatures start to dip into the 30*F. We have no heat source at the moment so time is of the essence.

We will check for rockwool today but if they don’t have it is there another working alternative? Thank you all for your help 🙏🏻

Okay I understand what you guys are saying thank you. Unfortunately we can not find anyone who has high temp ceramic blanket that’s why we were hoping to use the clay/perlite mix around the whole combustion unit.

As for the foundation we plan to put 2” of sand on top of the cement board and then add a second base layer of firebricks underneath the core. It is more costly but I’d rather overbuild it once than have to build it twice. Hopefully this is a much safer and better way to go. What do you guys think? You have far more experience with these than I ever will. Thanks

Fox and Byron,

Thank you for telling me this now before we start our second attempt. We would have been in big trouble. I will look at the book today and see what you mean Byron. We were going to insulate the whole J tube with clay perlite mixture. Is this okay?

Also (NOT trying to be a smartass) does it make a huge difference if the dimensions are a half inch off here or there? I assume the CSA, precise dimensions, are to ensure the “thermo siphon” works and the unit drafts correctly. Is there any room for forgiveness at this stage or is perfect 7.5 the only way? We are not masons so it is real tricky trying to get the bricks “perfect”. We can get them very close. Anyway thanks again!

After consideration with my wife we will be taking it all down and buying a wood stove. No just kidding we will be taking it down and insulating the floor better and then we will build it again. I hate to take it down after just getting it done but it is much easier to fix it now than later when it is totally finished. Thank you for the tip!

Perlite mixed with clay would be a nice base for it correct? On top of the cement board?

That is an excellent question I was so concerned with getting the width correct at 7.5 I don’t think I ever checked the height. The riser is 46.5 (should be 48) and the overall interiorlength of tunnel is 24 and both openings are at 7.5 or very close. But I forgot to check the height of the feeder which should be 16 I think I’ll have to look at the book for reference. Other than that is there anything else that looks odd? We used the clay slip to seal everything up. As always I appreciate all the help I can get thank you all 🙏🏻

Also that cement board should work fine as a base layer underneath the fire brick right? Under the burn chamber?

Quick update!

Vickey,

I am in Wasilla. That’s awesome you are in AK as well I love talkeetna! We have never built an RMH before but are very excited to give it a shot. We hope to start building this weekend. What class was it? I had no idea anyone did RMH out here(besides a handful of people) let alone having classes about it. Will you be building this summer?

Quick update for everyone! I have read all your replies but haven’t had a ton of time to be on my phone replying, we have been extremely busy trying to get our house insulated, wired, etc. thank you guys for responding and giving me insight/advice I appreciate ALL the help and wisdom I can possibly get so thank you!!

We have decided to go with an 8” J box style with 16’ of piping if we can fit that much in our tiny house. 14x24 feet. We are currently debating whether to go through the roof or the wall for the exhaust. I have read many different points and it seems the roof is the better option but I just hate to put a hole in the roof if I don’t have to. But anyway we got most of our material today and will begin building either this week or the next! I will keep you updated thanks everyone.