G Mack

Hi Scott. Yes saw your build post and am heading in that direction. Bought roof fire bricks yesterday. Thanks for your comments and build sequence.

Agree with water comment, but here the chimney is large enclosed wood structure (+/- 5'x5') so non issue.  Being that size w only one flue can easily have access to prime from bottom of vertical run w small heat or fan. Do you think that would provide enough draw to get up and running ?  Reason for all this is to avoid flue in house visually...but not at cost of function.

New build in off grid cabin. Am considering trying to keep exhaust flue under floor until it hits closet and chimney enclosure. Am not confident in it's draw or fire starting potential without smoking me out. Looking for more seasoned opinions as to whether stupid idea or possible. Thanks

No casting experience here. Thanks much for your input.

Ok... practical not technical. Just asking because I was thinking that may be a joint of differential expansion due to cast slab / fire brick differences as well as orientation ( wall / ceiling) and thought gasket fit was perfect there. Did you cast slabs at thickness similar to bricks for expansion reasons?  I seem to recall Peter mentioning castings should be on thinner side for quicker temp response. Always weighing strength, function and economy... I am considering 1.5" thick casting spanning 9". Any comments on that thickness?

Nice build Thomas...and thanks for sharing your knowledge on rmh design. Is the cast slab over burn chamber also gasket fit or mortared to top wythe of fire brick ?