Don Shares His Experience

Back in June I ran an oven building course at the Sustainability Centre in West Meon (nr Petersfield). Don Gribble was one of the attendees on that gloriously hot day. Don has now built his own oven and has shared his experience, and photos, for our benefit. There are some excellent words of advice, and some new approaches in his account so I advise you to read on.

Thanks for the sage words Don. Enjoy the oven!

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Dear Simon, I was one of your students on the June course at West Meon. Now I’ve just completed an oven and we have had our first pizza party. From starting the construction to our first pizza party took just two weeks.

It wasn’t all plain sailing. I emptied out the sand too quickly and it all collapsed and I didn’t even curse (according to my wife).

The Base

I made the base from second-hand Celcon blocks and pallets. The largest pallet I could find was 1.0m x 1.2m so it needed the top layer of blocks to be extended over the sides. I put a wooden frame around the centre bricks and filled around them with concrete. This wooden frame was useful for nailing the roof and cladding to. The plinth finished up as 1.3m x 1.35m and I then built the oven according to your booklet instructions, viz. 80cm internal diameter by 40cm internal height.

The Mixture

For clay, I used powder clay, bought in 25kg bags from clayman-supplies.co.uk in Chichester. I chose a white clay known as Hyplas Ballclay This is about the cheapest clay available and costs just £11 a bag. My son and I mixed it one part powder to two parts builders sand. We found the easiest way was to mix it up dry by hand and then to puddle it with very little water added. For the outer layer another friend helped and he did the mixing with a shovel – once again hard work but easy to get the right firmness. For the insulation layer we mixed the powder clay with water until like thick batter (or yoghurt) and poured it on to wood shavings. We found that this did not hold together as balls which could be dropped, but it stuck well to the inner dome when just shoved on in handfulls.

Quantities

You may be interested in the quantities since your booklet has some misleading advice [remember that Don used powdered clay here and I used wet clay in my book – SB]

  • For the dome we used 10 25kg bags of builders sand.
  • For the first layer, we used 4 bags of sand and 2 25kg bags of powder clay.
  • For the arch and blendings we used half a bag of sand and a quarter of a bag of powder clay.
  • For the insulation layer 7cm thick we used more than expected, namely, 2 bags of powder clay
  • For the outer layer which we made only 5cm thick, we needed 5 bags of sand and 2 1/2 bags of powder clay.

Finishing off

As you can see from the photos, I prettied up the oven by nailing on palings and used these as support for a plastic sheet roof. There is a large 1.2m x 1.2m sheet of plywood under the centre of the plastic to stop it melting. The final photo shows that I have added a melamine/plywood working surface as a support for the aluminium peel. We plan to roll out our pizza dough direct on to the floured peel so that we can put it direct into the oven. We have a long BBQ fork to reach in and help pull the pizzas out on to the peel.

Pizzas

Our very first pizzas were decidedly crunchy because they picked up sand from between the bricks. Our second pizza party was really successful. We built a large softwood fire and pushed it to the back after about 1 1/2 hours. Then, before putting the pizzas in, we brushed the hearth quickly with a bristle brush to remove ash and sand.

There are, perhaps, one or two ideas which you might like to incorporate into a future edition of your booklet.

Arch and Chimney first

Incidentally, there is another thought which you might find useful. Because my first dome collapsed I was left with an arch and a pile of sand. The second time round, I built up the sand around the chimney to give a good shape to the smoke escape route. As a result, this oven breathes beautifully. I reckon that for everyone it would be best to build the arch first, then build the sand dome and the connections to the chimney, and only then put on the first layer of clay. This allows you to make a much better entry to the chimney – easier than reaching up inside through the arch.

I do hope you find this interesting. Thank you for starting me off with a wonderful course at West Meon.

Don

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1. Building a Clay Oven – The Basics

[PLEASE NOTE THAT THE LINKS TO THE OTHER 7 PARTS OF THIS ‘HOW TO’ CAN BE FOUND ON THE LEFT HAND COLUMN. ALTERNATIVELY JUST CLICK THE LINK AT THE BOTTOM OF EACH SECTION TO GO TO THE NEXT PART]

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?

Background

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.

Materials

  • 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

Equipment

  • 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!