Newbie dome question - 2.5" thick instead of 4.5?

[Cheesehead]

Re: Newbie dome question - 2.5" thick instead of 4.5?

My curiosity is because one of the Newbies in this strand above pointed out that the firebricks don't get fully hot on the opposite side of the fire, so why so much insulation? (As you can see, I like to understand what I'm doing rather than just "do the usual!")

As the newbie in question I'd like to say that I'm planning on going with the full amt of insulation if not more, both underneath and on top. I'm also trying to understand what I'm doing and how the design works... in particular, how much "thermal mass" (heat capacity of the oven relative to the rate of heat flow outwards) is required.

[Neil2]

Re: Newbie dome question - 2.5" thick instead of 4.5?

"So the base of the oven will not be on top of the fill above the wall, but on the same slab that the wall rests on."

Sounds OK. Fills will settle somewhat more than native ground Differential settlement is the concern.