With the concrete dried in, it’s time to build the plinth, which will bring the cooking surface of the oven to a more accessible waist height.
We’re making the plinth from treated railway sleepers cut to size of £19 Each (for a double length sleeper chopped in two). Each sleeper is 120cm long x 10cm high x 20cm wide; so when placed in a square ‘cheek to nose’ the total diameter from edge to edge is 140cm. The diameter of the hole in the middle will then be 100cm by my calculations, which may be wrong.
Build the wooden ‘box’
- • Place the first ‘layer’ of the square in the centre of the concrete base with the wood sitting ‘nose to cheek’ to form a perfect square.
- Ensure that your square is square using the method pictured below and described in the previous post.
- • With a partner – to ensure the wood doesn’t ‘slip’ out of shape – drill two holes, equally spaced into the top of one of the pieces of sleeper sitting with its ‘nose’ to the adjacent sleepers ‘cheek’. Drill this hole at a 45 degree angle, stopping when you hit the other sleepers ‘cheek’ (you’ll feel something in the way the drill moves change). We found it helped to keep the structure square for your partner to watch the gaps/joins in the wood for signs of it moving out of place, and for them to brace themselves against the sleeper being drilled or hammered towards, with their hands touching any places the wood touches a neighbouring sleeper on a corner, so as to notice any ‘unsquaring’. (Not sure that’s a word…)
- • Place a long (approximately 4 inch) nail into the drilled hole, with a partner holding the wood together to stop slipping. Hammer this nail into the other sleeper at the 45 degree angle. Repeat with the second nail. This is known as ‘toshing’.
- Repeat in all corners of the square untill you have something that looks like this:
- Now simply add your next layer on top of the first, ensuring that where one side sat ‘nose’ to the adjacent sides’ ‘cheek’, it now sits the other way round. The photo below may be a better guide than my garbled explanation.
- Now tosh your nails on the long side of your sleepers, on the inside, into the sleeper below. It’s crucial here that you and your partner work together to keep the structure square. You can put as many nails into each length as you like, though three should suffice.
- If you’re feeling twitchy and want a little extra stability, you can drill and screw corner brackets into the corners.
- Keep building until you’ve reached your desired height, then sit back and have a cuppa. Well done.
We’re building ours to about 1m high; waist height.
Filling the inside of the Plinth:
- 1/2 Fill the inside of the plinth with rubble (or in our case, bits of excess concrete and bought hardcore). You can see some of the excess concrete scattered around the garden in the pictures. This will go in as well as £15 worth of half a cubic meter of 40mm to dust MOT filling stuff you can get from pretty much any hardware store (do shop around as I found prices varied wildly).
- • Fill the gaps between the rubble as best as possible with smaller stones / pebbles. This should minimise ‘heavage’ as the materials move and settle.
- Now I’ve put a layer of sand, followed by empty bottles arranged to fill the hole in a single layer. Surround these with vermiculite or sand, or other insulating filler; this is you heat sink. Remember to leave exactly enough room for your bricks on top.
- You can now either arrange your bricks till they fit perfectly into the gap you’ve left, or cement them in and cut them to size. Either way you should end up with a lovely, smooth brick floor.
- Have another brew and stretch out your back – shoveling all that filling is hard work!
Our next chapter in the pizza oven saga will be the first layer of the oven dome…
I’d love to hear about any projects you are working on right now.
Hope you’re having a great week,