web analytics
cracking in hearth slab - Forno Bravo Forum: The Wood-Fired Oven Community


1 of 3 < >

Forum Page Loading Response

Forum Members:

We have received feedback regarding recent issues with page loading response time. We believe the slow response issue stems from the analytics we added with the new Forum. We are in the process of reconfiguring those elements and, after an approximate 24-hour time period for the reconfiguration to run, we anticipate a return to normal page load times. Thank you for your patience!
2 of 3 < >


Hello, Forno Bravo Community Forum members.

As many may have noticed already, the Community Forum site was briefly down today. While working on scheduled routine maintenance, we encountered an error when trying to add a software update. As the site is now back up and running, some of you may notice that some recent data has been misplaced from November 10th up to today. We are currently working on resolving the issue. The forum has full operational capabilities and we encourage all forum members to continue actively posting in the threads.

We apologize for any inconvenience that this issue may have caused you. The Forno Bravo family values each and every member of our community. If you have any issues or concerns, please feel free to let us know on our issues thread here:


Thank you for understanding.
3 of 3 < >

Forno Bravo Forum Thread Message

Hello, Forno Bravo Community Forum Members!

The Forno Bravo team has heard the feedback in regards to the community forum. We wanted to take the time to re-enforce our commitment to a fully engaged Forum with professional moderation.

Our top priority as a company is to fix all forum errors and issues that you are experiencing. As we are swiftly working on these problems, we want to say that we highly value the Forum Bravo Community Forum and every single community forum member.

We have set up this thread so that every member can address any concerns, issues and questions about the forum. Please feel free to ask whatever you would like in regards to the forum; let us know what issues you are experiencing so we can work on resolving them as fast as possible. However, we stress that we would like constructive engagement, so please be specific about the issue you are experiencing.

Thank you for all of your patience and continued support.

Link to topic: http://www.fornobravo.com/community/...with-new-forum
See more
See less

cracking in hearth slab

  • Filter
  • Time
  • Show
Clear All
new posts

  • cracking in hearth slab

    After running the oven for a few days, today up to 400C, some hairline cracks developed at the edges of the hearth slab at the middle of each side. So, four small cracks, one on each side. Has anyone had this happen?

    It seems to be due to expansion of the centre of the slab directly beneath the oven relative to the cooler edges. These cracks are not a worry but probably could have been prevented by placing additional reinforcement along each edge of the slab.

    The oven is sitting at 300C at the moment and the underside of the slab shows 60C. Is this high? Are we getting too much heat leakage through the 50mm CaSi and 40mm perlite insulation?


  • #2
    Only time is going to reveal the significance of the cracks...

    In my view, the significance of your cracks is likely very small. The cracks could be serious if; 1) You didn't use a good recipe for the concrete, 2) Didn't cure the concrete properly, or, 3) didn't use proper steel reinforcement. The plans are designed to support more weight than your oven, so, you can make several variances to the plans and still have adequate support.
    Lee B.
    DFW area, Texas, USA

    If you are thinking about building a brick oven, my advice is Here.
    Our One Meter Pompeii Oven album is here.
    An album showing our Thermal Breaks is Here.

    I try to learn from my mistakes, and from yours when you give me a heads up.


    • #3
      Re: cracking in hearth slab

      60C is pretty high. Sounds like a wet oven to me. A bit too late to back off with the fire now. Keep firing it will fire better and the bottom of the slab will be cooler as you drive out the moisture. The water under the floor is about the hardest to eliminate.
      Kindled with zeal and fired with passion.