Key Takeaways:
- Regular bricks or concrete are not safe in very high heat (explosion risk), lack durability and can crack even after first use.
- Proper fire bricks offer safety and great baking performance for years.
- Fire bricks are not only for complex pizza oven builds with a dome. They can also be used for a simple DIY mortarless design that cooks fantastic pizza.
To understand if fire bricks are necessary or not to your wood fired pizza oven or outdoor fire pit, follow this article to find out.
If you are planning a DIY outdoor oven in your backyard, you have probably wondered about materials. It is tempting to use whatever old building supplies you have laying around to save money.
This article will cover what fire bricks are, what are the dangers of using regular bricks or concrete in high temperature environments and why proper fire bricks are the way to go for durability and your cooking performance.
What Are Fire Bricks?
Fire bricks are specialized ceramic blocks designed specifically to withstand extreme heat without cracking, crumbling or exploding.
Unlike standard building materials, fire bricks are engineered to store heat. They absorb the intense energy from your wood fire and the cooking area stays hot very long.
A proper wood fire can push the internal temperature of your oven well past 800 degrees Fahrenheit. Standard building materials simply cannot survive those extreme temperatures for very long.
Fire bricks, however, are incredibly heat resistant because of their dense, specialized composition. They are fired in kilns at massive temperatures during manufacturing and as their name says, they are meant for high temperature applications.
What Are Fire Bricks Made Of? (Refractory vs. Clay)
Generally there are two main categories when shopping for fire bricks for an outdoor oven. Let’s break down the differences between standard clay and higher-grade refractory options. Both types serve a purpose, but one is usually much more suited for a DIY wood fired oven.
Clay fire bricks
Traditional clay fire bricks are made from special fire clays that naturally contain high levels of silica and alumina. They are an excellent choice for a pizza oven.
Clay fire bricks are dense, heavy, and hold heat well beautifully for baking breads and pizzas. For most home DIY projects, standard clay fire blocks are exactly what you need to get the job done and strike a good balance between affordability and performance.
High alumina fire bricks
There are also high alumina fire bricks, which are heavily engineered refractory fire bricks. These contain a much higher percentage of aluminum oxide.
This added alumina gives them an astronomical temperature rating, often used in commercial steel forges or massive industrial kilns. They can withstand constant, punishing heat around the clock but are total overkill for DIY projects.
Why Not Use Concrete or Regular Bricks? (The Exploding Risk)
Regarding safety, regular concrete may have some moisture stored inside. With very high temperatures the water inside concrete evaporates and expands.
This can crack concrete or in a worst case scenario can cause it to even explode. Not a good picture if you’re thinking about a pizza night with family and friends. In the below video you can see how concrete can explode with enough heat.
Final Verdict: Are Fire Bricks Worth It for a DIY Pizza Oven?
So, are they completely optional, or an absolute necessity? The verdict is clear: specialized fire bricks are 100% required for a DIY pizza oven.
Skipping them to save a little bit of money will only lead to increased risk of someone getting hurt. Best case scenario concrete and regular bricks will just crack when you build a proper fire.
Choosing fire bricks will give you a safe baking experience, food safe cooking area and years of durability.
Read next: How to build a mortarless DIY pizza oven with just 47 fire bricks 4 fire brick slabs