With the structure of the pizza oven complete it’s time to add insulation to the dome. The oven will work okay without it but adding an insulation layer will mean the oven heats up quicker, retains heat better, and will mean less fuel is needed so it’s a pretty good thing.
I bought some ceramic fire blanket from Amazon for £20 and used some old chicken wire to hold it in place around the dome. Use some pliers to twist the wire and get it to hold it’s shape.
The next step is to add a layer of render. The render is a mix of 4 parts plastering sand with 1 part lime and 1 part cement.
You’ll also need some plastering tools (plastering hawk, trowel, float, etc) plus a mixing paddle you can use in a power drill will help.
The render will hold in place very well due to the chicken wire so make sure you push it in but try not to compact the fire blanket.
The added benefit of the fire blanket insulation is that is will trap heat in the oven and so the render will not get hot and crack.
Once the whole dome was covered I keyed it to give the second layer of render something to stick to.
Next up in part 9 and the final part of my build I’ll add a second layer of render onto the dome and also plaster the rest of the oven.
Hi,
Did the render from the sand, lime and cement withstand the heat? I’m currently at the final stages if finishing my pizza oven, but I have ran out of the castable refractory cement I was using on the outside. I was searching for a cheaper alternative to the refractory cement and come across your build.
Has there been any problems after using the mix you have recommended or had it held well and you would reccomend finishing it with the classic render?
Many thanks
Anthony
Hi there,
I’m really impressed with the detail to which you’ve gone too… I’m in the process of hoping to immulate your efforts!
Quick qs – how many 1/2 bricks do you think you used for the dome? And if going back again would you use fire bricks for the dome?
Thanks for your time.
John
Hi John, To be honest I’m not too sure how many I used! I went skip diving and got as many as I could and having a look at some of the photos I’d say I must have used between 50-70 house bricks. These were cut in half.
As I was building the oven a layer at a time it meant I could always get more bricks if I needed.
As for Firebricks for the dome… that would’ve made the project a whole lot more expensive. I think the floor needs firebricks to ensure the pizza base cooks, but the tops of the pizza’s cook really well with the flames etc, so no I don’t think I’d use the firebricks.
Good luck with your build.
Hi
Loving the blogs. I’m looking to build a yoga ball oven but on an angle like yours.
Regarding positioning how much extra thickness did the blanket and render and to the oven?
Thanks
Mike
Hey Mike, on top of the bricks I’d assume the blanket and two layers of render added about 2 inches extra thickness.
Good luck with your build.
Anyone used a vermicrete mix on top of the fire blanket and chicken wires instead of just sand/lime render! Can you then render on top on the vermicrete?
I’m don’t think the oven needs more insulation in the form of vermicrete. It would work fine, but personally I have my oven hot and the outside it pretty cool. It warms up after a couple hours, but I think the ceramic insulation does a good enough job.
Hi,
Once built, do you need to cover an outdoor pizza oven with an insulated waterproof cover?
It’s pretty weather proof apart from the door, so I usually cover with tarpaulin during the winter. If the inside does get damp then it just takes longer to heat up and drive the moisture out.
I was wondering if I could render my oven with only 1 inch of ceramic blanket and how would that affect the process? Just because I thought the blanket was already 2 inches but it was only 1 inch and I already put the chicken wire on it and it was fitting really well. Also i was thinking could I just put another inch on top of the chicken wire and then put more chicken wire over that inch thick blanket insulation and then render it thank you in advance for your help