RMH questions and rmh set up in a yurt , fire brick heat riser insulation , high heat fire mortar ?

ok ill start with the set up hi and thank you guys for such an awsome webpage my set up is in a yurt on a well built platform im going to use store bought fire brick and free cycled
red brick im thinking that a 4 inch stove pipe system would work best because its a 16 foot yurt the bench for the small diner table is going to be 5-6 feet long made out of red brick rocks and cob mix with red soil found on the property i live on the heat riser will be made from fire brick #1 what should i insulate the heat riser with ? do i need to insulate the heat riser ? #2 can i use cob slip as the mortar for the heat riser ? if not what is the simplest mix for high fire area on the heat riser ? or what is the easiest way to do refractory cement ? i have seen a video on youtube and they say to use fire clay and something im not sure because its not clear in the video im going to use one of the smaller barrels i think its a 15 gal does that seem like it would heat a 16 foot yurt ps i am going with the rmh so i dont have to get up at night and re stoke the fire does this system seem like it will keep a yurt heated for 8 hours after its been heated ? im currently using a vogalzang box wood stove and it gets to hot easy

Hi Tim; Sounds like you have the rmh bug ! First thing you need is a copy of ianto's book rocket stoves .These things are great! I have only built one , its in my greenhouse, I can't tell you how nice it is to let a fire burn out at ten at night ,cover the feed tube and like magic its still 50 degrees the next morning while its 20 degrees outside. I have heard that a four inch system can be hard to make flow well and that for a first timer a six inch system will be easier to make work. Black stove pipe can be spendy, but after one 2' stick in your horizontal transition area you can switch to hvac pipe in 5 foot sections (available by mail or in person from home depot) Perlite is what you would insulate the heat riser with. You will need a 30 gal barrel to cover your heat riser. yes cob slip with fire clay will work as mortar. You might consider using a 15 gal barrel and a 6"piece of sonitube and pour your own heat riser using a mix of perlite,fireclay , fiberglass and if you have it some powdered refractory cement. I will include pics of mine so you can see what i'm talking about.

thank you for the reply i will use a 6 inch system then maybe even 8 for good flow i was going to do a firebrick heat riser insulated with something like rock wool or ? reason being that metal ect breaks down when i build i try to always use the strongest materials and design will cob and fire clay stick and stay in place ?

i am going with the firebrick like in this video of ernie and erica at 5:20 ernie and erica interview
wondering what they insulated with ?