Insulation is undoubtedly the most important part of building a pizza oven or a bread oven. While the current standard assembly is in a box (cubical) structure, others also opt for a dome assembly, which offers a more authentic look. What materials should you choose? How should you proceed? Discover our tips based on the assembly of the **Ephrem L’Authentique Pizzaiolo** wood-fired oven, with an interior diameter of 90 cm.
INSULATING A WOOD-FIRED OVEN IN A DOME
1/ On a flat and stable surface, build 15 cm concrete block supports, then create a reinforced concrete slab measuring 150x150x10 cm*, larger than a standard assembly. Allow it to dry for approximately 15 days.
2/ Assemble the wood-fired oven according to the instructions provided, up to the installation of the first flue liner or the connection nozzle and the start of the stainless steel flue, before beginning the oven insulation.
3/ Completely cover the oven with a flexible roll of rock wool (ideally 10 cm thick). You can also use the insulating fiber roll sold by Ephrem, applied in double crossed layers.
4/ Place a fine mesh directly over the insulation roll to hold it in place; it will also serve as an anchor for the concrete.
5/ Prepare a vermiculite concrete mix using a cement mixer, following the ratio of 4 parts vermiculite to 1 part refractory cement, and don’t forget the water. For **L’Authentique Pizzaiolo**, this means approximately **300 L of vermiculite** for **75 kg of cement**. The concrete should not be too liquid—add the water gradually. Apply a uniform layer of about **20 cm** over the entire oven.
6/ Let the concrete dry, then protect the structure with a waterproof finish to prevent water infiltration. Complete the smoke exhaust flue according to the instructions.
The entire insulation should be at least 20 cm thick all around the oven once completed.
INSULATING A WOOD-FIRED OVEN IN A BOX STRUCTURE
1/ On a flat and stable surface, build 15 cm concrete block supports, then create a reinforced concrete slab measuring 142x142x10 cm*. Allow it to dry for approximately 15 days.
2/ Prepare a 2 to 3 cm layer of lean mortar using standard cement to set the oven floor, ensuring it is level, without adding joints between the slabs. Remove any excess mortar around the edges of the floor. Wait 24 to 48 hours for the floor to dry before proceeding.
3/ Assemble the wood-fired oven according to the provided instructions.
4/ Build a 10 cm concrete block wall around the oven, then install the smoke flue (20×20 cm interior flue liners or a ⌀200 mm stainless steel flue).
5/ Completely cover the oven with a flexible roll of rock wool (ideally 10 cm thick). You can also use the insulating fiber roll sold by Ephrem, applied in double crossed layers.
6/ Cover the entire oven with vermiculite concrete mixed with refractory cement to reach a thickness of 15 cm above the oven. Use approximately 500 L of vermiculite, 100 to 150 kg of cement, and about 70 L of water (a ratio of 5 parts vermiculite to 1 part cement). Alternatively, you can bury the oven and the rock wool under a 15 to 20 cm layer of dry 0/4 sand. Build a shelter above the oven, leaving an air gap of about 20 cm above the insulation to create a decompression chamber.
*Based on The Ephrem L’Authentique Pizzaiolo wood-fired oven
Important :
- Take into account the differences in slab dimensions depending on whether the assembly is in a box structure or a dome.
- DO NOT SEAL THE ELEMENTS TOGETHER UNLESS SPECIFIED IN THE INSTRUCTIONS.
- Always insulate the oven.
- Do not overlook the importance of the smoke exhaust flue.
- Follow a very gradual first firing (2–3 days).
- Our material is naturally frost-resistant; however, make sure to properly shelter the structure to protect it from the elements.
- Enjoy the pleasures of wood-fired cooking to the fullest and send us a photo of your finished oven!
Photography and illustration: Romain Dussaulx, Antoine Pilette. Source: Ephrem Fusion The diagrams on our website may not be used for commercial purposes by any third party other than Ephrem Fusion.
