Building a Pizza Oven for your Patio or Porch
The basic “Pompeii” or semi-circular pizza oven is one of the most popular and it is the one I based my oven on. You’ve probably seen this kind of pizza oven before: a half dome that usually sits on some type of brick foundation. This style of pizza oven has its roots in ancient Pompeii — hence the name.
Basically you need the oven (dome-shaped); the oven must have a chimney. The interior of the oven will be constructed out of refractory bricks and cement to keep the heat in. It’s really that simple. The link www.fornobravo.com/pompeii_oven/oven_dome is fantastic and maps out the dome-building process complete with pictures. Let’s move on:
1) Size IS everything: You want an oven size that is at least 36″ and 42″ (internal diameter). You probably don’t want to construct anything smaller than 30″-32″ oven, because while you can build something smaller, there’s not too much different in the price of materials so go bigger and you’ll appreciate it later. The 42″ brick oven is large enough for a majority of home cooking requirements,
2) Bricks and mortar: The secret is in the bricks and mortar. The bricks heat up quickly and are efficient at holding the high heats required for cooking the perfect three-minute pizza. The Pompeii Oven is also very efficient with wood fuel and at holding heat. .
Building mortar and refractory mortar are not the same. Refractory fire clay based mortar is not used as the ordinary mortar used by bricklayers. House building mortar joins bricks by keeping them separated. In wood ovens, refractory mortar should strictly be used only where flat firebrick joint is impossible.
3) More on mortar: General building mortar is for the base. You don’t want your base to absorb heat. Use the following measurement: 6:1:1 – Sand, cement and Lime. The lime is used only to keep the mortar soft so you can work longer. Don’t want to use the lime? Use a measurement of 4:1 – Sand and cement.
4) Build a model on a flat space to get your exact measurement for the bricks you are using (see photo of dome shape).Do not allow space for a mortar joint, as you will be setting the edges of the bricks facing inside the oven flush with each other. To set the position of your oven on your hearth slab, first measure and mark the center of the slab from side-to-side (left/right) and the center of your oven floor back from the oven landing and vent landing. Then, using a string and marking pen, build a compass half the diameter of your oven (18″ or 21″), and mark the circumference of your oven floor.
The dome itself a series of self-supporting circular brick chains that curve inward, until they meet at the keystone at the oven top. The first chain is a ring of brick cut in half and standing on their ends, with the thin edge (2 1/2) facing inside the oven. You can adjust the exact diameter of your oven to match the size circle that your bricks form, so that you do not have to cut a brick in your first chain.
My personal recommendation is a top-mounted chimney. As you work your bricks inward on the dome, allow for a 115 inch circumference. Basically this involves not “tapping” your done. You will insert an aluminum chimney later
5) Concrete cladding: Cladding is minimum 5cm – 2″ thick concrete layer applied over the firebrick dome of any style. Concrete cladding is very quick and easy to do and amount or cost of material cladding requires is very low. For best results, it’s important to have both height measurements right. When you have your job done, you want the fire to burn well inside. This ratio is 62% to 64%. Most precise example for home oven:
After you’ve covered the oven — let it sit for at least 4 days. I would allow 1 day to get your bricks and cement, 1 day for construction and 4 days for everything to dry. On the 5th day you should be eating pizza!
