Insulating your wood-fired oven is undeniably crucial in the construction process. While the conventional approach involves using a box, those seeking a more traditional experience might consider an authentic dome assembly. The choice of materials and the process itself play a significant role. To help you with this, we provide guidance based on the assembly of the Ephrem L’Authentique Pizzaiolo 90cm oven.


1/ First, prepare a flat and stable surface for your wood-fired oven. Assemble 15 cm breeze block supports, ensuring they are securely in place. Next, create a reinforced concrete load-bearing slab that measures 150x150x10 cm, which is larger than a standard assembly. Allow the concrete to dry for approximately 15 days before proceeding with the next steps.

2/ Follow the instructions provided to assemble the wood-fired oven, ensuring that you reach the point where the first ball valve or connecting pipe and the stainless steel flue are installed. Once you have reached this stage, you can proceed with the insulation of the oven.

3/ Cover the entire oven with a flexible roll of rock wool (ideally 10 cm thick). You can also use the roll of fibre insulation sold by Ephrem in double crossed layers.

4/ Position a fine wire mesh directly on the roll of insulation to hold it in place. It will also act as an anchor for the concrete.

5/ Make vermiculite concrete in a concrete mixer, using a ratio of approximately 4 parts vermiculite to 1 part melted cement, not forgetting the water. That’s about 300 litres of vermiculite for 75 kg of cement, in the case of L’Authentique Pizzaiolo. The concrete should not be too liquid, so add the water gradually. Apply a layer of about 20 cm evenly over the entire oven.

6/ Allow the concrete to dry, then protect the structure with a waterproof finish to prevent water from seeping through. Finish the flue in accordance with the instructions.

All the insulation should be at least 20 cm all round the finished oven.


1/ On a flat, stable surface, build 15 cm breeze-block supports, then create a 142x142x10 cm* reinforced concrete load-bearing slab. Leave to dry for around 15 days.

2/ Prepare a 2 to 3 cm layer of standard cement-based thin-bed mortar to build up the floor of the oven, ensuring that it is level, without making any joints between the slabs. Remove the excess lean mortar from around the floor. Wait 24 to 48 hours for the flor to dry before continuing.

3/ Assemble the oven according to the instructions provided.

4/ Build a 10 cm breeze-block wall around the oven, then create the flue (20×20 cm internal flue or stainless steel flue ⌀200 mm).

5/ Cover the entire oven with a flexible roll of rock wool (ideally 10 cm thick). You can also use the roll of fibre insulation sold by Ephrem in double crossed layers.

6/ Cover the oven with vermiculite concrete bonded with refractory cement to reach a height of 15 cm above the oven. Use 500 litres of vermiculite for 100 to 150 kg of cement and around 70 litres of water (1 dose of cement for 5 doses of vermiculite). You can also bury the oven and rockwool under a 15-20 cm layer of dry 0/4 sand. Make a shelter above the oven, leaving an air space of around 20 cm above the oven insulation, to create a decompression chamber.

*Based on the Ephrem L’Authentique Pizzaiolo oven


  • Take into account the differences in slab dimensions for box or dome installation
  • Above all, do not seal the components of the oven together when the instructions do not require it.
  • Always insulate the oven
  • Don’t overlook the importance of the flue pipe
  • Start by heating up very gradually (2-3 days)
  • Our material is naturally non-frosting, but make sure that the work is well sheltered to protect it from bad weather.
  • Enjoy the pleasures of cooking over a wood fire without moderation and send us a photo of the finished work.

Editorial: Ephrem Fusion
Photography and illustration: Romain Dussaulx, Antoine Pilette. Diagrams may not be used for commercial purposes by any third party other than Ephrem Fusion.
Source: Ephrem Fusion