Loads of pics here
First we had to set some cavity blocks. There’s quite a slope on TOG’s yard so the left side was about 20mm lower than the right. The left side blocks had to be raised to compensate. After the bottom 4 blocks were set, the others were simply stacked on top. Lengths of timber, painted with bitumen paint for waterproofing, were laid across the top, Now we had a suitable platform to build on.
Next we built a timber frame 100mm high, as a mold for a lightweight insulating concrete. Filled the frame with dry vermiculite to find out how much was needed. Made up some wire mesh for reinforcing, some wire rope as a carry handle, and some lengths of cable to make holes for temperature probes. Mixed up 6:1 vermiculite to cement. Levelled out the mix in the frame, then left it to set.
Laid out red bricks to decide the best size and shape. Decided on 3 bricks wide (lengthwise) and 8 bricks deep. Stacked up bricks to make the sides. Used small amount of weak cement/sand mix to seal the gaps in the bricks. Cut 25mm angle iron to support the bricks used for the roof. Lit a small fire to get some heat into the oven and really dry it out. Covered the sides with aluminium foil and rockwool slabs for thermal insulation.
Connected up a makeshift flue and lit a fire directly in the bricks. After a few hours the dial thermometer was almost off the scale at 300 deg C. Time to start cooking! Made a peel from a baking tray and brush handle. Pushed the fire to the back and brushed the hearth clean. Made about 20 pizzas from both readymade bases and dough. There were no leftovers 🙂
They were cooking in about 3 to 4 minutes, with one turn half way through cooking time. 12 hours after letting the fire go out, the inside was still at 101 deg C! Pizza oven makes a great patio heater too 🙂