Building my 1st outdoor adobe oven - a few questions for the pros

[Mactrev]

Hello , I am building an outdoor adobe oven and had a few questions for the pros concerning dimensions. My oven will have a 32" interior diameter. Many cob oven builders suggest I use this formula 32" x .75 = 24" high dome & 24" dome x.63 for an approx 15" high doorway ..... or .... brick oven builders suggest 32" x .50 = 16" high dome & 16" dome x .63 for a 10" high doorway. I would like to have a 18" wide door so that I could cook a 16" pizza occasionally. Is one formula strictly for abobe clay ovens & one strictly for brick pizza ovens?? This oven will be used for cooking pizza,breads, roasts & anything else that sounds good !! Any suggestions or comments would greatly be appreciated.