A wood-fired oven is a necessity if you want truly authentic Neapolitan-style pizza. Wood-burning ovens cook pizza faster than any other method, providing an earthy taste that can't be duplicated with gas or electricity. Building your own wood-fired oven may seem intimidating, but it's really quite simple. While it does take some physical strength to work with the materials for your oven, the building process itself is quite straightforward.
Draw a few rough sketches of the oven and determine its size. Most ovens have a floor of 20 to 30 inches, but your needs will depend on what you want to bake. Remember that the walls of your oven will add a lot to its outside dimensions, and plan accordingly.
Lay the oven support. Stack breeze blocks into a rectangle or cube a little larger than the oven itself. Remember to alternate blocks in each layer, so that the spaces between blocks don't line up. This provides a more stable surface. Your base should be about waist high for the person who'll be using the oven the most. This base lifts your wood-fired oven up to a convenient height, and keeps heat from being transmitted into the ground. Mortar the breeze blocks if you choose.
Apply stucco to the base if you wish. Stucco is not required for your oven, but can make it look better. Buy commercial stucco, or mix a mortar of one part masonry cement and three parts sand. Apply the stucco with a trowel in two or three thin coats and allow it to cure.
Arrange firebricks on the flat surface of the oven support, in the shape of the oven you wish to build. Round ovens are traditional, but rectangular oven bases may be easier to build. Place each brick about ¼ inch from the next, to allow space for mortar. You can also use regular bricks, but they are more likely to crack.
Mortar the bricks. Remove bricks, one at a time, and apply mortar between them. Trowel the mortar on in an even layer, and place the bricks back into position. Repeat until all bricks have been mortared.
Smooth the mortar. While it's still wet, use your trowel to smooth the mortar and remove any excess. A good cooking surface is smooth, with no blobs of dry mortar. Allow mortar to set and dry completely.
Place the first course of bricks for the walls. Leave an opening in the front that's large enough to accommodate any food you wish to cook in the oven. As in section 2, space the bricks 1/4 inch apart. Adjust the bricks until you get the oven shape you want.
Apply mortar to the bottom and sides of bricks. Remove the bricks one by one, and mortar them as you did for the base.
Place additional courses. Add new layers of bricks over the first, until you reach the desired oven height. Remember to stagger the seams between bricks for a stronger oven. Remove excess mortar while it is still wet. Allow the mortar to harden.
Form the arch. Fill the oven with wet sand in a dome or cylinder shape. Then, lay bricks in an arch over the dome to create a ceiling for the oven. The wet sand supports the bricks until the mortar is dry. Once the mortar is set, remove the sand. Spray the inside of the oven with water to clean the oven fully.
Mix the concrete. Pour a bag of concrete into a wheelbarrow or other large container. Mix it with water according to the manufacturer's instructions.
Build the concrete structure. Some oven styles require reinforcement, in the form of a metal or wooden structure inside the concrete. If your oven plans call for it, create a wooden or metal structure around the oven bricks to support the concrete. Builders making round ovens can usually forgo this structure.
Apply concrete. Trowel concrete over the bricks in a thick, insulating layer. Make sure this layer is the same thickness throughout. Thin spots in the concrete could allow heat to escape.
Apply stucco. You can create a uniform appearance by applying stucco to the outside of your oven. Use the same techniques for stuccoing the oven itself as for stuccoing the oven support.
Allow your oven to dry completely before starting a fire.