Concrete molds and brick forms have been around since time immemorial. The Roman Empire was built with massive iron reinforced concrete buildings poured using angle iron and wood molds, while brick arches build against wood forms are used for virtually every type of span or wall opening.

While it’s possible to build large free-standing bricks dome without impossibly-large-to-build forms—the Duomo in Florence is a great example—that type of construction is left to the experts. In fact, building a hemispherical dome, where the top of the dome is equal to its radius, out of brick is pretty much impossible. For example, building a basic 40″ diameter hemispherical Pompeii Oven can, hypothetically, be done, but it requires a great deal of expertise and patiences, and it slows the process down by a huge amount, waiting for mortars to set.

The process of building a brick pizza oven is made significantly more challenging when you want to build a dome that is lower than a hemisphere, such as a Naples style pizza oven. That’s because the outward thrust of the lower dome pushes the first course of the dome outward, reducing the stability of the dome. In general the lower the dome, the greater the outward thrust, which also explains why the very tall catenary arch is the most structurally sound type of arch.

Cast pizza ovens, using a mold, are an easy way to build a pizza oven dome that offers both the low oven dome and the structural integrity that you want. Modern casting material offer the same cooking properties as brick, while giving you the strength to cast the oven dome in the shape you want.

Traditionally, commercial pizza oven companies use either steel or fiberglass molds to cast the dome. They de-mold the dome using a release agent on the mold, essentially pulling the casting away from the mold. The molds get a lot of wear and tear, and they require a lot of maintenance.

At the same time, the molds for barrel vault brick ovens are typically made with plywood. The shape of the arch is drawn on a piece of plywood, and cut with jig saw, and then the top of the form, made with bendable 3/8 plywood is created to the form. After the brick arch dries and becomes stable, but form is lower, and removed through the oven opening.

Cast in place molds for round, dome shaped ovens are different. First, the mold must be easily removable through the narrow oven opening. That rules out steel, wood and fiberglass, leaving only two options. Sand and cardboard.

Sand is a very inexact material that is difficult to form into accurate shapes, that takes up a lot of space, is heavy to work with, and need to be disposed of in the end.

That leaves cardboard. In fact, cardboard is the perfect material to build a pizza oven mold. It can be accurately cut with a CNC controller laser, meaning the oven can be designed on a CAD system to get the exact design you want. Cardboard is rigid enough to hold the casting material in place, while it dries and then cures. And finally, it is easy to break down and remove through the oven opening.

We will be producing cardboard pizza oven molds in five sizes—24″, 28″, 32″, 36″ and 40″.

Check back to see how we progress.