Chimney flue question

[Cort]

david s Ok I have casted a small flue out of home brew. My oven is about 26 inches. I have a 4 in chimney pipe. It’s not installed yet. I planned on installing it like davids has illustrated. I still need to insulate my dome. I was hoping to vermicrete right over the ceramic insulation. No chicken wire . 2” if insulation and 2” of vermicrete over that. Finally render with quikcrete quikwall. I am open to changing anything you think needs addressed. Thanks for helping me out. I really appreciate it!

[david s]

After finishing the vermicrete give it a couple of weeks drying before starting the drying fires. Once they’re completed do the outer rendered layer. I like to wrap the whole oven in cling wrap for a week to retain moisture in this outer layer for strength enhancement.
When doing the vermicrete you will find it difficult to apply and make it stand up vertically from the base. So you can build it up to only about 6” high and leave it for 24 hrs to harden. This makes it far easier to then build on top. As you go higher it is leaning in and it becomes far easier.

[Cort]

Ok so no fires until it’s insulated.Thanks for your guidance much appreciated!