The Perlite aggregate combined with Portland cement and water produces a lightweight insulating concrete that is ideal for pizza ovens. This type of concrete is widely used in the construction of wood-fired brick-style ovens, as it is able to withstand the high temperatures and fluctuations that come with the cooking process. However, it is important to note that not all concrete is suitable for use in a pizza oven. For areas that come into direct contact with the furnace fire, such as the hearth, dome, or other high-impact “hot face” areas, a mixture composed of refractory products like crushed refractory bricks (known as “grog”) or refractory cement should be used.
When mixing concrete for a pizza oven, it is important to get the consistency right. The right consistency is achieved when a handful of concrete can be formed into a ball the size of a tennis ball and thrown half a meter up into the air and still remain together. To achieve this, you need to mix Portland cement (PPC) with water to create a high-quality cementing material. If the consistency is off, your concrete block may lack a hard finish on the outer surface or you may find small stones at the bottom of your pizza or between your teeth.
It is also important to ensure that your foundation is solid. The supports for your outdoor pizza oven can be made of concrete, breeze blocks, house bricks, or even old railway sleepers, but they must be strong and level as the oven will be heavy. After an initial setting of concrete, cover your work with plastic sheets and spray it with a thin stream of water to avoid rapid loss of water at the edges and surface. When it comes to heat-resistant concrete, there are two main types: refractory bricks and refractory concrete.
Refractory bricks are more heat-resistant than refractory concrete and should be used exclusively in areas that come into direct contact with the furnace fire. Refractory concrete can also be used in these areas but should be mixed with a refractory mixture to improve its quality. Additionally, you can add some standard fireclay to this mix if desired. In conclusion, when constructing a pizza oven it is important to use the right type of concrete and ensure that it has been mixed correctly.
Refractory bricks should be used in areas that come into direct contact with the furnace fire while refractory concrete can be used in other areas but should be mixed with a refractory mixture for improved quality. Additionally, make sure that your foundation is solid and level as this will help ensure that your pizza oven lasts for years to come.