Pizza oven dome out of bricks

A brick pizza oven dome is usually constructed as either an igloo or barrel dome. Both shapes are constructed in much the same fashion with bricks, mortar and usually with a supporting frame. Construction of an igloo dome does not necessarily require a frame if completed by a competent brick layer. Fireclay or refractory mortar is not normally required. Some cracks may develop with regular building mortar however these will be within the oven and not readily noticeable.

Internal brick wall

1. Construct a supporting frame for the bricks to lay against. This may be made as with the cob dome out of wet sand and newspaper. Alternatively you can use scrap wood to make the shape.
2. Mix the mortar to the correct ratio and a workable consistency, and begin laying bricks at the base of the oven structure. Ensure you closely follow the outline of your supporting frame structure. Keep in mind that the outside of this structure will not be visible so concentrate on the aesthetics of the internal wall.
3. Continue laying bricks until your supporting structure is covered.
4. Ideally your oven's vent should be placed in front of the oven door. Begin construction of the hood oven the front of the oven door leaving a hole for the chimney.

After constructing the internal brick wall you will need to cover the brick with an insulation layer to further improve the heat retaining properties of the oven.

Pizza oven dome out of cob

How to construct the dome out of cob

Once the hearth has been establish you may begin to build the wood fired pizza oven dome. Domes constructed out of cob usually consist of clay, soil water, and hay to act as a binding agent. As cob is a soft and malleable material before it dries, a supporting foundation is usually created to hold the cob in place during the construction and drying phase.

Begin by placing moist sand as a mound onto the hearth. The small amount of water will allow for the sand to be molded into place. Continue to add sand to create a mold of the inside of the pizza oven. You may want to make use of a piece of wood with a curve sawed out to help model the send into a uniform shape. Keep in mind that the walls of the pizza oven will be placed on this sand mound and thus the final size of the oven will be substantially larger. When the sand mound is complete, place wet newspaper over the mound. The moisture will keep the paper in place, and the function of the paper will be to allow for easy removal of the sand at a later date.

Cob Mixture Ratio

1. Mix cob either on the ground or on a laid out tarp. Cob is made from a mixture of soil (or Aggregate (Sand or small stones)), clay, water and hay / straw. Mix the components together with your feet until completely combined.
2. Take a handful of cob and shape into a fist sized ball.
3. Forcefully place the cob at the base of the oven. You want to be forceful so as to ensure a good bond between the cob and surface.
4. Continue to place cob as a single layer around the base of the oven. The top of the cod lay should slope towards the oven at a 30degree angle.
5. Smooth the joints between each cob piece.
6. Begin on the second layer of cob. Continue until the sand/newspaper is completely covered.
7. Start again to make a second layer of cob insulation on the first. Ideally your pizza oven cob wall should be at minimum 4 inches (10cm) thick. The thicker the wall the greater the insulation and thus the high the heat generated, and longer the cooking time sustained.
8. When the cob wall is finished you will need to cut an oven door and chimney vent if desired. Use a knife or garden tool to slice into the cob and remove excess material. Alternatively when building the cob wall you may leave these sections devoid of cob so as to ski this step.
9. The final cob oven may be finished with a render of clay to give a more pleasing appearance.

Allow the oven to slowly dry oven a period of days. If the oven dries too quickly then the likelihood of cracks occurring is increased. Once the oven dries you can repair any cracks with additional clay, and carefully remove the sand and newspaper from the oven door.