web analytics
Using firebrick instead of a pizza stone - Forno Bravo Forum: The Wood-Fired Oven Community



I'm Peter Reinhart! Ask Me Anything! Monday, February 15, 2016 7:00-8:00 pm EST

To kick off our AMA feature, we have invited author, chef and master bread maker and host of Pizza Quest, Peter Reinhart, to be our first host! Peter will be in the Forum on Monday, February 15th, from 7:00 - 8:00 pm EST. If you are unable to be online during the live session, you can post your questions in the sticky post. Peter will answer those questions during the live session on February 15th. You can view Peter's answers to your questions as well as what happened during the live session in the session thread.

Ask Me Anything New Forum Feature

You will notice a new forum at the top of the main page called, "Ask Me Anything". This forum will be used for live one hour "Ask Me Anything" (AMA) sessions hosted by people who are knowledgeable in different areas pertaining to wood fired ovens. How it works:
- Each AMA will have a "sticky" thread where the community can post questions they would like answered during the live session. This will allow everyone to participate even if you can't be online for the live session. These questions will not be answered by the host until the live AMA; if you need an answer quickly, you should post it in the appropriate Forum area for the community to respond.
- Another thread will be posted for the live AMA. Registered users who are logged in during the live session can interact with the host by asking questions and receiving responses.
- The live thread will remain in the AMA forum to view after the session.

We hope you enjoy this new feature! Please let us know if there is a topic that you'd like to have as an AMA and we'll look for a host!

Forno Bravo
See more
See less

Using firebrick instead of a pizza stone

  • Filter
  • Time
  • Show
Clear All
new posts

  • Using firebrick instead of a pizza stone

    It appears that many have learned the hard way that pizza stones are fragile.

    In my area (Seattle) one can purchase fire bricks for less than $2 each (e.g., from Mutual Materials). Firebricks form the hearth of a standard wood-fired oven and are a great cooking surface. Standard U.S. firebricks are 4.5 inches by 9 inches by 2.5 inches thick. "Splits" are half that thick.

    You can lay out a pattern of firebricks on your oven rack. It doesn't matter if there are small gaps and irregularities -- that's the way it would be in a wood-fired oven anyway. (A big gap would be a problem, however.)

    I've seen speculation regarding the heat-up time. This is a classic heat conduction calculation. Lets say the bricks are initially at 80 F. You place them with edges touching such that the large faces will be the cooking surface, i.e., with the shortest (2.5 inch) dimension vertical. To a good approximation, all heat conduction will occur through the large upper and lower faces.

    In the best case (which won't actually happen), the oven temperature quickly reaches the desired value (say 600 F) and the brick faces quickly reach and sustain this temperature. Heat gradually conducts inward until the bricks reach a uniform temperature equal to the oven temperature.

    Typical fire bricks have a density of 1860 kg/m^3, thermal conductivity of 1.03 W/m-K, specific heat of 1.05 kJ/kg-K, and thus a thermal diffusivity of 5.3e-7 m^2/s. Using this value and the temperatures given above, within 15 minutes the average temperature of the brick is 469 F. After 1 hour it is essentially at a uniform temperature of 600 F.

    In other words, one hour of preheating should be plenty for full-thickness bricks.

    For splits, 15 minutes after the oven reaches its operating temperature should be plenty.