A little while ago I was asked to repair a pizza oven that was damaged through vandalism. The oven had been a bit ordinary for some time and the outer shell had been cracking and breaking away. This had allowed water to get under the outer shell compounding the problem and allowing moisture to stay in the oven and therefore the oven was having trouble retaining heat and needed to be lit days before it needed to be used.

After the vandalism the outer shelf was half gone so I decided to remove the whole outer shell and start over with an improved design !

Supplies

Materials I used are as follows -

1 x Bag of general purpose cement

1 x Bag LIme

1 x Bag washed sand

1 x 2m x 1200mm roll of chicken wire

1 x Bag of Lite Perlite (https://melbournefirebricks.com.au/new-products/litefill-perlite)

1 x sml bottle of Boncrete (optional)

1 x Acrylic waterproof membrane paint

Step 1: Preparation

I began by scrapping away all the old loose and flaking outer shell and then chipped away the hard bits that where still stuck. In my case this was relatively easy as most of the shell wasn't adhered very well.

When I had a nice smooth surface I cut and shaped the chicken wire to fit roughly into the shape of the Pizza oven.

I'd also recommend laying down some covering tarps on your bench tops if you have them. I didn't do this and it's quite a messy process and I spent heaps of time cleaning up afterwards.

Step 2: Mixing New Sealing Coat

I mixed up the new surface coat of render mix in a wheel barrow with a shovel and the quantities depend on the size of the oven you are repairing.

The general mixing ratios are as follows.

· 5 parts Lite perlite

· 1 part washed sand

· 1 part lime

· 1 part general purpose cement

· I also added a little bondcrete

Add water and mix to a consistency that is not to dry and not to wet. It needs to form a ball if a little is tossed in the air a few times. About the consistency of toothpaste.

Step 3: Applying the Render Mix

You can buy a foam float (link below) that has a slight concave that is very useful for shaping the render mix. It's also quite easy to make one if you have a foam square and cut some away yourself. It doesn't have to be perfect as the mixture is quite rough and can be shaped by hand a bit later on.

- Work from the bottom of the oven to the top to a thickness of about 25mm and try to cover all the chicken wire.

- Use the foam float to get a round shape but it doesn’t have to be exactly smooth on the first coat.

- Let dry for approximately 24 hours.

- Apply a second coat to the same thickness and pay more attention to the finished shape and smoothness of the finish.

- Let dry for another 24 hours

https://melbournefirebricks.shop/collections/oven-accessories/products/float

Step 4: Finishing Off and Waterproofing

Once both coats have been applied and allowed to dry the last step is to seal in with a waterproof membrane. You can get this in various colours to match your surrounding decor.

https://melbournefirebricks.shop/collections/oven-...

- Light the pizza oven on a low heat for approximately 12 hours and then on a medium heat for at least another 12 hours.

- Keep some heat in the oven for another 24 hours so that all the moisture is removed.

- While the oven still has some warmth in it and no moisture apply the waterproof membrane paint with a brush and get in all the crevices.

- Allow to dry for a further 24 hours before using.

I did this repair over a year ago and the Pizza oven has been used over a dozen times since and its works better than ever. The heat retention is much better and the oven takes much less time to warm up.