Inner arch top heigh vs outter arch? Door Design question

[stevef22]

To allow smoke to slowly "roll" over inner arch and out the flue. What is a good difference?

I understand inner arch side to side should be slightly smaller so door can have a good seal.


But what about height?

Imaged attached of some of my designs.


1 inch taller in onside?




1/4 taler on inside?

[david s]

Allow about an inch on both sides and the top.

[stevef22]

Thank you.