Finally it is time to start building your oven. For this stage you’ll need:
- Builders sand
- Old newspapers
- Tape measure or long steel ruler
- Clay-sand mixture
You are going to build a large sand dome – the former which supports the first clay-sand layer of your oven. I really enjoyed this part of the process mainly because it provided a practical justification for the hours I spent building sandcastles on the beach with my stepson Thom when he was a little lad (to be fair it was usually me who wanted to build the sandcastles!).
Tip lots of sand onto the brick floor of your oven. I’m not sure how many bags I used but I remember being amazed at how much was needed to build up the dome to the required dimensions. Remeber the outside of this dome will form the inside dimensions of your finished oven. The base (widest part) of my oven is the same dimensions as the length and width of the brick floor (80x80cm). I decided to make the height of my oven approximately half that of the diameter (40-45cm). Build up the dome, moulding and sculpting with your hands until it is the desired height and a nice shape. A top tip from Steve at River Cottage HQ is to keep checking the shape of the dome from above, so periodically stand on your plinth to get that birds-eye view! Once you are happy with the shape, firm-down the sand with your hands.
Next you need to add a layer of wet newspaper. This makes removal of the sand from inside the cavity much easier later on. It is a little tricky to get the paper to stick but persevere and you’ll crack it. Thats the dome complete. Now you are ready for your first oven layer.
The First (Oven) Layer
If you are doing this alone make sure you leave 3 or 4 hours to build your first oven layer. I made the mistake of starting in the early evening and ended up finishing it at midnight wearing a head-torch!
Take some of the clay-sand mixture from your wheelbarrow in cupped hands and form it into an elongated/rounded brick shape. Press this first “brick” against the base of the dome and compress it into place, with one hand holding it against the sand former while the other makes a “karate-chop” type movement (using a straight hand) against the “domeward” side of the brick. This creates a wedge-shaped “brick” (sloping towards the dome) which helps when adding layers above and also removes any air bubbles from the mixture which may subsequently expand and crack the oven. You are aiming for an oven layer that is approximately 7cm thick and the simplest way to keep check of this is to measure the bricks periodically against a marked stick or even a piece of straw. Add another “brick” next to the previous one and, using the same technique, mold it into the first. Repeat the process until you have laid “bricks” around the whole circumference of the dome.
Begin laying “bricks” on top of this first layer and continue, round and round, up and up, until you have completely covered the sand dome former. Remember to keep checking the oven layer thickness as you go. Don’t worry if you end up with some variation in thickness – as you build the oven layer up you might find that the base widens out a little from the weight of “bricks” above. Smooth and shape the oven layer into a neat, coherent shape and don’t forget to check from above.
That’s it! Your first layer is complete. You need to leave it to dry for a few hours before you cut the hole for the oven entrance – which I’ll discuss next.