1. Building a Clay Oven – The Basics


Welcome to the first installment of building a clay oven.  This post will cover:

  1. Background – including what is a clay oven?, what can you use it for? can I build a clay oven?
  2. What you will need – Materials and equipment
  3. The build order
  4. How long it will take to build
  5. How long will it last?


The Finished Clay Oven in My Garden

The Finished Clay Oven in My Garden

I assume that most people who have found this site will already know what a clay oven is, however it is probably useful if I define what I mean by a clay oven for the purpose of this blog.  Before I do that though a quick word about nomenclature.  I will use various names for the clay oven interchangeably, these include “clay oven”, “traditional clay oven”, “wood fired oven”, “pizza oven” and “traditional bread oven”.  If you browse around the web you will also see the name “cob oven” being used – cob being a mixture of clay and straw (+ or – sand).  As I am not using straw in my build I will not use the term cob but will include it in my definition as this type of construction is probably the most ancient of all clay ovens.  Another name commonly used is earth oven.

In my definition then, a clay oven is any hollow, dome-shaped structure constructed out of clay, clay and sand or clay and straw, used for the purpose of baking and roasting food.  It has a brick floor and usually a chimney.  Most traditional clay ovens are built outdoors and may or may not be covered with a simple roof structure.  You will find some amazing examples of clay ovens, particularly huge pizza and bread ovens, built inside restaurants.  The oven I have built is much smaller but still suitable for cooking for large groups of people.

Clay ovens are amazing things.  They look incredible and create a feature in any garden, large or small.  The most important reason for having a clay oven for me though is for cooking.  If you have never eaten a pizza cooked at 450°C for 1 minute in a clay oven – you have never eaten a pizza!  Just imagine a thin, crispy, slightly charred base covered in hot melted cheese, olive oil, garlic, sun-dried tomatoes, dried cured sausage, smoked ham, anchovies…do I need to continue?  How about loaves of hot bread cooked to perfection, cracked open and smothered in real dairy butter or a large joint of lamb or pork belly cooked slowly with herbs over night in the oven’s residual heat, falling off the bone when you come to carve it the next day.  OK OK enough of the M&S style adverts already!  I think you get the picture.  Cooking in a traditional clay oven is wonderful, it feels different and definitely tastes different.

Building your own clay oven is not difficult.  I am by no means an expert when it comes to DIY but am normally happy to give things a go.  I have never built anything like this before but managed to complete my oven without any major disasters.  The beauty of building a clay oven is that you use mostly natural and, if you are lucky, recycled or free materials.  There is something very primeval about building one of these ovens.  The process is a direct link back to our ancestors who would have used similar techniques for cooking many millennia ago.  I thoroughly enjoyed building it! It is a very physical and tactile experience – you will handle and form every single piece of clay, sand and wood that goes into it and the finished product is something that you will be extremely proud of.

What you will need – Materials and equipment

OK lets crack on with getting this baby built!  Here I will list most of the equipment and materials you are going to need to build your own clay oven.  I will provide details such as quantities later on as I step through the build process.


  • Builders sand
  • Clay
  • Water
  • Rubble / hardcore
  • Wood shavings
  • Normal building bricks (e.g. London Bricks) for oven base
  • Large wooden “beams” or bricks or stone for plinth (I used beams as you will see later)
  • Cement if you are building plinth out of brick
  • Right-angled brackets and screws if constructing plinth from wood
  • Glass bottles (optional)
  • Old Newspapers
  • Plastic rubble sacks
  • Wood for burning in the oven


  • Saw (chainsaw?)
  • Wheelbarrow
  • Bucket
  • Tarpaulin or thick plastic sheeting
  • Shovel
  • Spirit level
  • Large knife
  • Hands and feet!
  • Wellington boots or other sturdy boots

The Build Order

So you have your equipment and materials list.  Next I thought it would be useful to outline the order of construction.  This will also form the basis for the rest of the posts in this series, each post providing details for each stage in the build process.  Simple – I hope!  As you might have guessed already, I love a good list so here goes another:

  1. The plinth foundation, plinth and brick oven floor
  2. The clay-sand mixture and puddling technique
  3. The dome sand-former and first layer or the oven layer
  4. The oven entrance and chimney
  5. The wood shavings and clay slip layer or the insulation layer
  6. The final clay-sand layer
  7. Firing the clay oven
  8. Cooking in the clay oven

How Long Does it Take to Build a Clay Oven?

Construction involves quite a few steps and each step takes variable amounts of time to complete.  Probably one of the most time consuming processes is puddling (mixing with your feet!) the clay-sand mixture.  One batch (two buckets of sand to one bucket of clay) will take about an hour to an hour and a half depending on the consistency of the component parts.  If you get a group of people to help then obviously you can speed the process up.  Many feet make light work of puddling!  Building the oven layers is also very time consuming and you need to leave drying time between each layer if possible.  The other major factor which effect the length of time it takes to build your oven is the weather.  You can’t construct anything other than the plinth if it is raining and it does tend to rain quite regularly in the UK!

What with interuptions (both weather and non-weather related) from start to finish my oven took 6 weeks to build on my own.  However if you have a spell of good weather and a few helping hands (and feet) I think you could build one in a week.

How Long will a Clay Oven Last?

To be totally honest I have no idea how long it will last.  I have only had mine in my garden for a few weeks now.  The good people at River Cottage HQ suggest a couple of years but obviously this will vary by your location, local temperatures, weather conditions, air moisture content, the type of cover or shelter your oven is housed in, the amount of use your oven gets, the type of clay you use for construction and many other factors.  They are pretty robust but they are organic structures and they do crack after repeated heating and cooling.  This is not a problem if cracking only effects the outer layer – you can fill the cracks with spare clay-sand mixture.  However, once you get cracks in the internal oven layer then the oven’s days are numbered.  I say, don’t worry too much, enjoy it and use it and if it falls apart you can build another one!

175 thoughts on “1. Building a Clay Oven – The Basics

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  3. Hi Simon
    I am looking to build a clay oven as part of my forest school lessons with my forest school group. we have 2 hour sessions once a week. will it be feasible to build it in stages over a few weeks? I have 7 students in the group so they can take turns to do the different stages, and lots of feet to puddle . I am trying to source the clay from my local brick works.

  4. Hi Simon
    I decided to tear apart my oven and rebuild it. There was a big crack in the middle, also i didn’t really take my time on shaping it and as a result it didn’t have a terrific shape. So, I’m starting over. I noticed, however, that when I broke the clay, it didn’t really feel like brick. Instead of breaking into pieces, it more kind of crumbled away. Perhaps it never really fired properly? It was quite thick in some areas, and i only used it perhaps a half dozen times. My question is, could i possibly use that clay/sand again? I took a rubber mallet to it and it really all kind of fell apart into powder. I’m hoping I can just use it over again, pound it down really well and add some water to it. The only thing is if I add anything to it, I won’t be totally sure of the sand/clay ratio.

    Thanks for any info


    • Hi Peter

      the situation you describe is perfectly normal. The clay in these ovens will never vitrify – they just don’t get hot enough (more details here – https://clayoven.wordpress.com/2014/06/16/beware-of-the-clay/).

      I would say yes you can reuse the mixture. Smash it to bits or just soak in water. You’ll need to obviously rehydrate. The consistency on build day will depend then upon the amount of moisture let in the mixture.

      Let us know how you get on.


  5. Hi Simon, I have followed your Website and managed to build my clay oven during this last summer. I made a few minor changes to your instruction and took heed of some of your “shortcomings”. We had a cracking lamb kleftico in late September which was also enjoyed by our neighbours. Just to note, I sourced terracotta clay from a local potters supply (12.5 kg packs – several) and mixed each pack with 25 kg of sand. For the insulation layer I bought a mega bag of wood chips from a pet shop and mixed with clay slip as suggested. It all worked well. I’ve rendered the oven with a mixture of clay, sand and cement which has given it a protective crust. Additionally I have made a cover from old polycarbonate roofing for winter protection. Thanks again for your insight and know how – looking forward to many many clay oven days. John Greaves

    • Hello John… Thinking of using cement as you did!! Just wondering what ratio of cement ; sand ; clay? Did the Shape stay in tact with no cracking anywhere? Cheers

      • Hi Derek
        I cannot remember the ratio but it was quite a runny clay slip mixed in with thick layer of straw and chicken wire over this to hold it all in place. The cement render then went over this and I did it quite thick. There was no cracking but I have sold the house and moved back to England but old neighbours say the new homeowners still use the oven frequently. The shape stayed fine.

  6. Simon, I found some clay in a brook behind my house. Will I still need to mix sand with it or will I be okay to use it straight from the ground as it already has dirt mixed in? Thank you

  7. HI there
    I’m in the process of building a clay oven, although not with the base that you are suggesting. I have made a foundation out of old slate tiles. It’s not as high as yours, but if it works out it may lead to a more permanent oven. The clay I found was very moist, and was quite hard to dig. But now that I have it home, it’s starting to dry out. Can I just stomp on it to crumble it up, or should I saturate it with water again to soften it before adding sand? Still need to figure out the sand/clay ratio.

    thanks, great site!
    Summerside, PEI Canada

    • Hi Peter, if you could grind the dry clay to a powder, you could add to sand, add some water and mix in a cement mixer. Otherwise rehydrate it and puddle it into the sand at a 2:1 ratio (sand:clay).

      • I’ve been looking at it, and stepped on a couple of pieces, which turned to powder quite easily. So what i’ll think i’ll do is stomp a bunch of it down, and measure it to put on my tarp. Then I’ll add the sand and go from there. Two more questions and i’ll stop bothering you :-). how much sand/clay do you normally need for this project, and can I use beach sand? I think i have about 9 or 10 five gallon buckets of clay. And not that I’m cheap, but I’ve been having fun finding the things I need instead of buying everything. I live on an island so there’s lots of sand, but it’s not builders sand. I’m hoping it will do.

        Thanks again!

      • See my latest post (or the book) for quantities. As for beach sand, it’s illegal to take it in the UK. Not sure about your part of the world. Any sand will do though so, if you can get it legally, go for it!

  8. Hi Simon, I bought thee book last year and am going to build the oven in spring. what clay would you recommend and where can I get it from?
    Thanks Jacqui

    • Hi Jacqui, use any clay you can get your hands on. It really doesn’t matter. If you can find a local source in the ground, go for that, otherwise you might have to buy some. Go for the cheapest potters clay you can (if they say you need something special – you don’t!).

      Best of luck


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