The Fresh Loaf

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a few thousand pounds of clay...

patman23's picture

a few thousand pounds of clay...

Hey folks,


I recently inherited a home in SoCal with a few thousand pounds of wet bagged clay on the property that was used for making pottery. Id like to use it to make a wood fired clay oven. I’ve seen some videos on building cob ovens and ovens made from fire brick but nothing from wet, unformed clay. I also have 20 or 30 firebricks on the same property that id expect to use for the floor of the oven. 

As for uses, Id like to use the oven for bread and roasting meat, and of course pizzas. 


Any suggestion on what Id need (if anything) to combine with the clay like maybe straw or something?


Id still want to use a good layer of vermiculite over the clay and maybe concrete or another clay shell over that with some broken pieces of pottery pressed in for astetics... 

I’ll be pouring four concrete corners to bolt some 6x6s to so as to keep it one place and give it a good foundation that’ll resist settling. Any suggestions or resources would be appreciated.  


mikedilger's picture

I have bags of clay and building a clay oven has long been one of those projects I plan to eventually get around to, so I've looked into this a little bit.

I've never done it, but I've seen multiple references of mixing the clay with sand first, and that this is a serious chore.  People 'dance on" the clay and sand mixture with bare feet to sufficiently mix it.  Takes a large crowd all night long, all night, all night, all night long (uh, sorry there, I got carried away).

Also, if your clay oven is outdoors exposed to the elements, it will eventually erode.  If it can be in a barn or under a roof of some kind it would survive much longer.

Do let us know how it goes!  with pictures!

David R's picture
David R

You need only one thing, but you need it very badly:

You need the advice of someone who has already succeeded at what you're doing.

Or, you decide that you're happy to "be the guinea pig" and risk your time and energy on something that might or might not do what you want in the end. If you have that time and energy to spare, and you don't mind the risk of having a big reinforced clay cave that's not really an oven, then hey, why not? ?

pmccool's picture

You can search for either term and get a lot of guides and videos.  Here's one.


prettedda's picture

I have built a cob oven which is pretty much clay mixed with other things. Sand for the thermal mass and straw for structural. Clay is clay whether you dig it up or buy it. Mixing is not very hard just get the amount of water right but you can use a heavy electric drill with a drywall wisk. 

Biggest challenge is getting the balance between thermal mass and insulation. If I were to build again, I would insulate underneath with rigid board insulation - foam glass. I insulated above with loose vermiculite above a clay she'll then covered with clay over a bamboo frame. That seems to work well. Kiko Denzer (cob oven builder) recommends against combining clay and concrete bcs concrete traps moisture.

In short, you are considering a cob oven and there is a lot of material on how to build cob ovens.

patman23's picture


Ive been told that folks who build themselves a wood fired oven have the first oven they built, but then they dream of the oven they sohould have built. Im kind of trying to avoid that by asking loads of questions. Ive done a good bit  of research thus far but wanted to talk to folks that have actually done it. The property I inherited was my mothers and she was a potter. That said, Id like to find a good use for all of this clay. Plus, Im an avid baker/cook so it seems like a match made in heaven. 

Ive looked over Denzer’s ovens and really like them. There is also a guy named, Ernie Wisner that had developed a double chamber cob oven that seems to be a solid improvement. It’s my understanding that Wisner and Denzer are friends. Anyway, Denzer and Wisner both recommend using old bottles as insulation for the bottom of the oven. I think that I’ll be usining something closer to what you’ve mentioned. 


Any other info or suggestions you have are much appreciated.