web analytics
Will the bottom of the hearth slab get hot? - Forno Bravo Forum: The Wood-Fired Oven Community

Announcement

Collapse

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

Will the bottom of the hearth slab get hot?

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Will the bottom of the hearth slab get hot?

    Hi All,

    If I build a 5 inch thick hearth slab on top of the stand, and then put 5 inches of perlcrete on top of that and then build my hearth bricks / oven floor on top of the perlcrete...will the botton of the 5 inch thick hearth slab get hot? At all?

    What If I left a piece of plywood between the stand walls and this hearthslab as a slip plane? Would it burn up? Smolder?

    Thanks!

    Drake
    My Oven Thread:
    http://www.fornobravo.com/forum/f8/d...-oven-633.html

  • #2
    the purpose of the insulation layer on top tof the hearth concrete slab is insulation. The idea is to keep just the floor of the oven hot and not lose the heat, through conduction, to the surrounding surfaces. A well insulated harth will yield very little heat transfer through to the concrete layer. It is probably prudent to remove the plywood support from the bottom of the structure. As you can see from the construction photos posted on this web site that there are temporary support pillars that are removed. Some folks have had problems of the concrete not releasing from the wood. There are ways around this, some are better than others.

    Comment


    • #3
      I have seen ovens, and we have built ovens, where you use concrete board to form the bottom of the hearth, and you don't have to worry about dropping the plywood form. Concrete board is saggy, so you have to brace it more, but you don't have to remove the plywood. It might be six of one and half a dozen.

      I would drop the plywood personally, even though it will not get hot undernearth the concrete bottom layer. The 5" vermiculite/vermiculite layer you are building will stop a majority of the heat.

      I talked with one builder who did not use the vermiculite layer, and his 6" concrete slab got very hot on the bottom, and lost of lot of heat out of th oven that way. I experimented with a thin sand only layer above a concrete slab once, and the bottom of the concrete got really hot, really fast. Scary.

      James
      Pizza Ovens
      Outdoor Fireplaces

      Comment

      Working...
      X