A wood-burning backyard pizza oven adds character and usefulness to any patio, outdoor kitchen or backyard area. Keep fire safety a priority when situating and building any outdoor fire structure and locate the oven away from buildings and combustibles that could catch fire from its operation. A brick oven takes some time, expertise and expense to build or have built, but a mud oven or earth oven is less complicated and expensive to build and is just as effective for baking pizza and bread.
Make a waist-high base or platform for the oven with retaining wall bricks or cement blocks. Dig a 2-inch deep rectangular area five feet by four feet to set the first layer of bricks or blocks into for stability. Place the first layer of cement blocks in the dugout area, creating a solid base. Continue stacking blocks until the platform is high enough, about five layers. Add a layer of firebricks on the top in the middle, leaving about a 1-foot border without firebricks.
Fill a wheelbarrow halfway with sand and add water to make the sand wet but not soupy. Mound wet sand on the inside oven base of firebricks about 3 feet high to form the oven.
Mix about six shovelfuls of clay soil, two shovelfuls of sand and a gallon of water on a tarp, picking up the corners of the tarp to mix well. Mix until the mixture is a thick consistency--not too soupy but not too difficult to stir.
Layer the mixture over the wet sand mound. Apply one inch of the mixture, leaving an 18-inch high by 18-inch wide area for the door in the front. Don't leave any bare or thin spots and smooth the mixture around the bottom of the sand mound, leaving no gaps.
Let the first layer dry overnight or up to two or three days.
Mix about six shovelfuls of clay soil, two shovelfuls of sand, six shovelfuls of chopped straw and a gallon of water on the tarp. Make sure the straw is distributed evenly throughout the mixture.
Apply a 2- to 3-inch layer of the straw mixture over the top of the previous layer, leaving no thin spots or gaps.
Let the second layer dry or cure for up to three weeks before use.
When the oven has dried well, scoop out the sand mound from inside the oven.
Place two stacks of 2 or 3 firebricks inside the oven, parallel to each other, about 8 inches apart, to build a fire between and place pizza trays on top of for baking.
Draw designs into the wet straw mixture after layering it over the oven form for an ornamental effect. Other decorative effects to create include pressing colourful stones or gravel into the wet mixture or adding tile borders.