Are Vermiculite Bricks Good? – Regular Bricks Vs Fire Bricks

Your DIY pizza oven project is going on, and you are looking to buy bricks for your pizza oven. Standard clay bricks cost you 0.60-1$ per block as per quality. But suddenly, you see a type of brick priced at 25-30$ for 4 units; your eyebrows suddenly get raised, wondering what bricks these are.

Are Vermiculite Bricks Good

Most probably, your eyes have caught the vision of vermiculite bricks, a kind of fire bricks. So, are vermiculite bricks good enough as they get priced? Yes, vermiculite bricks are an immaculate option, especially when making an outdoor brick pizza oven to bear the hottest burning woods.

So what is vermiculite, and how does it save your fireplaces from hazards and misfortunes? Let’s see below;

Are Vermiculite Bricks Good? How to Manage Temperatures

Firebricks are fundamentally different from ordinary clay bricks in terms of ingredients, as they have a higher percentage of Silicon dioxide. This boosts the temperature capacity to humungous 3000F degrees. But yes, you have lifted temperature-bearing power; now, what about the insulation for these highest temperatures?

This is where vermiculite befalls as a naturally occurring non-combustible material to insulate the most intensive heating temperatures. Also read, how you can repair the fire brick?

Are Vermiculite Bricks Good

You place a layer of vermiculite bricks as a buffer or inner layer of your pizza oven to insulate heat. Standard fire bricks are hard but porous. Vermiculite has the quality of being extra soft, thus, making the refractory bricks much softer after they are hydraulically pressed.

It further enhances the thermal conductivity, so the insulation. So, for your question, are vermiculite bricks good?

Yes, these are actually good as vermiculite bricks shield the outer shell of a pizza oven from inner heat when you burn wood like OAK or hickory that exhaust nearly 30K BTUs heating temperatures.

So, it stows you safe from a firing hazard.

Avoid These Things to Save Your Fire Bricks from Breakage:

Vermiculite bricks are undoubtedly vigorous substances when it comes to bearing heat. However, the life cycle of vermiculite bricks only depends on the cautiousness you give to these materials. So, when to tell your vermiculite bricks have completed their life cycle?

Normal cracks, like the thickness of hair threads, are acceptable. The only concern about their replacement is when firebricks slip from their position or fall apart, leaving a vacant space. Consequently, you can form an estimation that the time has come for a replacement.

Avoid These Things to Save Your Fire Bricks from Breakage

Otherwise, minor to somewhat moderate cracks are fine.

But you can enhance the life of vermiculite bricks by following these steps:

  • Don’t patch extra-long logs, as they can cramp and literally break.
  • Only use fully seasoned wood and manage the moisture content.
  • Remember, don’t overdo it. Overfilling your stove does more harm than good.
  • Moisture is the enemy of these lightweight fire bricks, so when you go for a cleaning, don’t let water or other liquid cleaning agents destroy all your project.
  • Manage heat, don’t unnecessarily light up your oven, as it’ll gradually kill the life of bricks.

How to Use Vermiculite in Your Pizza Ovens?

Vermiculite can be used as a mixture in the cement or directly as a buffer firebrick for heat insulation. Additionally, vermiculite pellets also get used in propane or LPG fireplaces like gas chimneys. This forms insulation and also provides good colors to the fire.

How to Use Vermiculite in Your Pizza Ovens

But in the case of steel and wood fired pizza ovens, you can employ them in the form of bricks. The thickness and length of bricks vary as the bricks are cut from pressed vermiculite board. But the most common thickness you’ll see in the market is the 25MM to 35MM.

Likewise, instead of bricks for outdoor wood-fired ovens, you can mix vermiculite with cement to make concrete. The amount of vermiculite varies as per the pizza dome size, but generally, the rule with the cement is 4:1. This will also act as insulation to thwart heat from slipping out of the pizza oven.

The Genuine Good and Bad Points of Vermiculite Bricks:


  • Can withstand against fiercest temperatures
  • Saves you and your assets and family from fire hazards.
  • Environment friendly as vermiculite can degrade in the soil
  • Free from toxic chemicals and asbestos
  • Low shrinkage when it comes under extreme heat
  • Extremely lightweight and porous
  • Soft to cut even with wood saw


  • Considerably expensive
  • A very delicate substance to store and maintain
  • Can’t sustain against moisture
  • In the case of bricks, you have to take Care of the length of logs as they can cramp and crack easily.

Bust the Myths – FAQs

Is vermiculite fireproof? 

Yes, they have been domestically and commercially in use for insulating fireplaces against the highest degrees of temperature. They are primarily used as a fire-retardant coating to avoid any fire hazard.

Is there a difference in fire bricks?

The most widely used bricks are regular and firebricks. So, yes, there is a difference in utilization, color, chemical formation, thermal conductivity and applicability, lifecycle, and cost. Traditional bricks are generally used in building structures, whereas firebricks are used in fireplaces for the purpose of kiln lining or insulation.

How to Cut Firebrick?

Fortunately, the firebricks are softer and more porous. They can be cut easily with an electric blade used for wood cutting. There are various ways to cut the firebrick. But it all depends on the thickness. For normal to high viscosity, you can place the brick at the deck of the electric blade. Clean the deck and measure the angles correctly. Start the blade and slowly cut the firebrick; stop the blade first, and then lift it to save the brick from unnecessary cuts.

The Bottom Line:

So, are vermiculite bricks good? You can absolutely see the good points dominating the demerits considerably. The only drawback I consider is the high cost. Vermiculite bricks are a really sumptuous shield against sizzling heating temperatures. An additional plus point is you can formulate vermiculite without any complex steps or methodology.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *