Clay sand ratio for cob oven

[Lake lover]

Hi all
I can't seem to find a sand to clay ration for a cob oven.

I have some clay recommended for WFO.s from a local clay producer.

I have access to sharp masons sand. Planning a 40 inch wide dome oven.

I poured the supporting base yesterday.

It will have to sit for a while as it cool outside.

Fire brick is bought for the floor, and flue liner.

Thanks all

[david s]

Re: Clay sand ratio for cob oven

Don't forget to insulate between the supporting slab and the oven floor.
I think the sand, clay proportion is about 50/50 and usually chopped straw is added to the mix to add reinforcing.

[Lake lover]

Re: Clay sand ratio for cob oven

Perlite is in place.