Sunday, August 21, 2011

Pizza Oven--Insulating with cob/adobe

Pizza Oven/Insulation added

Since far and away the most interest my art blog generates is for my home-made, adobe bread and pizza oven I thought I should reward all those random readers with an oven update.
As I said previously in my last Pizza Post, it is functional as it is now but would stay hot longer if it was better insulated. For a cob/adobe oven; insulation means: dirt/sand/clay mix but made into a slip by adding more water and then folding in hay or grass or sawdust. I had a big bag of woodshavings and sawdust from a neighbor's woodshop so that's what I used but I added some dried cut stemmy grass to give it a little more structural stablity.

Here is the process;
First I made some moist clay/soil mix and patched the few cracks that exist in the insulation layer I had built previously.

Then, I mixed up a wheelbarrow's worth of woodshavings/sawdust with clay/mud slip.
I mixed it with a shovel and then threw in a bucket of dried grass/stemmy clippings.
(Straw would have been better but I had a pile of cut grass).

Then I added about a two-inch layer, fistful at a time going around the base and then up the sides to meet a layer I had already added to the top. By slapping it on it didn't slump and the grassy bits helped meld the fistfuls together. I gently smoothed the surface and then added some scratches in the surface to help the next layer adhere/stick.
Now, I'll let it dry for a day or two and decide if I want to try to add a finish or smoother layer. It will take several days to dry out and I'll post again about how it works then.
But here is a photo of my last pizza: Potato and leek with garlic oil. It was tasty.


  1. Looks great and perfect for summer. I write guides on how to make this type of thing so I know a good design when I see one.

  2. Thanks for looking.
    The big "problem" is this is really a bread oven; 27" in diameter with about an 11" door.
    But since I use it more often for pizza; less mass and a bigger door would have been better.
    AND even when I bake bread I usually fill the oven only once so the additional mass is probably not needed.
    It's still just dried sand, clay and mud so when it finally fails (collapses), I'll rebuild it with a slightly different shape.