Building your own pizza oven is a dream come true for many who enjoy the idea of evenings spent entertaining friends and family outdoors while cooking the perfect homemade pizza for their hungry guests. Fortunately, this can quite easily become a reality for the DIY home enthusiast. The materials, however, will make a significant difference to the success of the oven.
Pizza ovens are usually built out of several materials, all of which can withstand heat to a certain degree. Concrete is usually used in some parts of a pizza oven, but it should be used sparingly in the areas that come into direct contact with the fire itself.
When using concrete in building a pizza oven, certain additives are usually employed to ensure the concrete can withstand the extreme heat of a pizza oven. However, the concrete is generally not used in any areas of the pizza oven exposed directly to the fire.
Can You Build A Pizza Oven Out Of Concrete?
Generally speaking, while pizza ovens usually consist partially of concrete, you are very unlikely to have success in building a pizza oven entirely out of concrete. This is mostly due to concrete’s inability to withstand extreme heat, especially when compared to a material such as clay bricks.
So, while concrete is likely to be used in a pizza oven for certain elements such as the suspended supporting slab or the mortar between the bricks, it is not advisable to use concrete in any areas that will have direct contact with the fire.
If the concrete is exposed to fire, you should make use of a refracting product such as crushed fire brick or refractory cement. This will ensure that the areas that are directly exposed to the fire will be able to withstand the extreme heat conditions.
This includes the mortar that is used between the bricks. By making use of a refractory compound in the mortar, you will be assured that the areas of concrete material that are exposed to the extreme heat of the fire will be better able to withstand the heat.
Fire bricks, which are clay bricks fired in a kiln, are the better option for use in any area of your pizza oven exposed to the fire. The mortar used between the bricks should be kept to a minimum and should consist of a refractory element, as mentioned above.
The type of concrete used – as well as the required mix of the concrete – will depend on the location of the concrete within the structure of the pizza oven. Another consideration is the degree to which the temperature fluctuates within the oven. This will have a big impact on the type and mix of the concrete.
If using bricks, those made of clay and fired in a kiln will function perfectly in a pizza oven as they have the ability to withstand the heat of a fire. Concrete bricks, on the other hand, will quickly start to crumble and become destroyed under the extreme heat of the fire.
Detailed Material Requirements For Building A Pizza Oven
The bricks to be used must be made of clay and should be the solid, burnt type. When it comes to the brick’s dimensions, they should be as uniform as possible to ensure ease of construction and an overall neat aesthetic.
Clay face bricks are a great option for a pizza oven because they afford a certain degree of uniformity and aesthetic appeal. This is particularly useful if the dome is not going to be plastered. Refractory fire bricks can also be used, but this may be an unnecessary extra expense.
As mentioned above, concrete bricks should not be used in a pizza oven because they will be unable to withstand the heat of the fire and will quickly start to crumble.
The mortar to be used is usually one that consists of fine sand, ideally building sand, with cement added. In most circumstances, a common cement with a 32.5 strength class will be adequate.
While refractory cement can be used, it is not completely necessary if the mortar is kept to a minimum in the areas directly exposed to the fire. This type of cement is exceptionally more costly than traditional cement.
Ensure the mortar is not overly strong. A ratio of approximately one bucket of cement to six buckets of loose sand will be sufficient, to which enough water should be added to form a plastic mixture.
The concrete used in the suspended slab of the pizza oven should be carefully made to ensure that it achieves the required strength. Firstly, the concrete should be accurately batched. This is achieved by using a full bag of cement and leveling off the containers with a plank or other straight edge.
Do not add too much water – simply add a sufficient amount that will help achieve proper compaction while ensuring the concrete mix remains workable. Compaction should be done properly, ensuring that all air bubbles are removed from the concrete.
The steel reinforcement should be correctly placed at the bottom of the slab, and it should also be fixed into place so that no movement occurs when the concrete is poured. The concrete should also be properly cured by ensuring it remains wet after setting. This can be achieved by covering it with plastic.
Construction Of A Pizza Oven
The place to begin with a pizza oven is the base. This is constructed out of concrete and is essentially a concrete slab built into an excavated section of the ground. The slab should be around 3″ or 75mm thick.
The next stage is the building of the base walls, which are usually constructed with brick. Around nine brick courses is usually sufficient to bring the base up to a good working height. Next, a suspended slab is built on top of the walls.
The next part of the project is the oven itself, and this should be constructed using brick. Stone is spread across the concrete slab and leveled before clay paving bricks are laid to form the oven floor.
Once the floor is complete, the dome and chimney are built out of bricks, leaving temporary support in place until the bricks have been set in place. Now your pizza oven is complete.
While certain parts of your pizza oven can be built out of concrete, it is not recommended that you build the entire oven out of concrete. This is because concrete as a material is simply not suited to being exposed to the extreme heat usually found in a pizza oven.