Foundation

Overview

If you are lucky enough to already have a hard solid surface like a patio area where you can build the oven then lucky you, because you can skip this stage of the build and move straight on to building the base.

Please Note:
The depth of the foundation and the thickness of the concrete will be dependant upon the type of soil on the site where you are going to build your oven. The steps below detail how I built my foundation which I felt was suitable for the earth in my garden. The earth was fairly solid and stable once the top soil had been removed. If your soil is very loose, sandy, or wet, then it would be best to dig deeper and to pour a concrete slab instead of using four individual slabs. If in doubt, then get some advice from a builder. The last thing you want is your oven to start to collapse due to weak foundations.

Materials

  • 3 bags of ready mixed multi purpose concrete
  • 4 bags of Slablayer
  • 4 600 x 600 x 38 concrete slabs
  • 4 pieces of 19mm x 100mm x 1800mm wood
  • Brocken slabs / bricks / hardcore

Tools

  • Spade
  • Rake
  • Canes or rope
  • Tape measure
  • Spirit level
  • Wheelbarrow
  • Rubber mallet
  • Hose pipe or watering can
  • Measuring jug

Download Photos

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Photos

Build Instructions

  1. The first task is to decide upon the location of the oven (and to get approval from your partner before you go digging up the garden)!. I found that using canes was a good way to clearly see how much space would be required for the oven. Rope laid on the floor could also be used. The area of the base is 1200mm x 1200mm but I marked out an area slightly bigger, around 1400mm x 1400mm. It is entirely up to you if you want to mark out and dig the exact dimensions or not.
  2. Now its time to start the serious work!..... Grab your spade or rake and start to clear any plants or weeds that are in the way, then dig down about 4 to 5 inches. Try to keep the bottom of the hole as flat as you can.
  3. Build yourself a wooden frame with internal dimensions of 1400mm x 1400mm. Using the 4 lengths of 19mm x 100mm x 1.8mtr wood. I cut the wood and then used one screw in each corner to hold the frame together.
  4. Lie the wooden frame inside the hole. Try to make sure that there are no stones under the wood, and that it lies flat on the soil. I used a spirit level on top of the wood just to make sure it was fairly level.
  5. Now take your pieces of broken slabs or bricks and place them inside the wooden frame.
  6. Empty 1 bag of ready mixed concrete into a wheelbarrow and add 3 litres of water. It's easier to add 1 litre at a time and mix the concrete after adding each litre of water.
  7. Once mixed, use a spade to place the concrete into the wooden frame and then use the spade to spread out the concrete up to the edges of the wood.
  8. Repeat this with the other 2 bags of concrete so that the area within the wooden frame is covered.
  9. Wait until the concrete has dried out and then empty the 4 bags of slablayer into the wooden frame and use a spade or rake to spread it out so that it fully covers the area within the wooden frame. Try to ensure that the slablayer is evenly spread and level.
  10. Use a sprinkler from a watering can or hosepipe and soak the slablayer. Then place the four 600x600x38 slabs onto the slablayer.
  11. Using a rubber mallet, tap the slabs into position and check that the slabs are as level as possible by using a spirit level.
  12. Check the dimensions of the slabs once you are happy that they are level. They should measure around 1200mm x 1200mm
  13. Have a cup of tea (or something stronger), stand back and admire your work!