web analytics
Insulating dome with Insulfrax only - but how much? - Forno Bravo Forum: The Wood-Fired Oven Community


1 of 2 < >


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.
2 of 2 < >

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

Insulating dome with Insulfrax only - but how much?

  • Filter
  • Time
  • Show
Clear All
new posts

  • Insulating dome with Insulfrax only - but how much?

    I plan to build my oven on a metal stand so that I could potentially move it to a different location in my back yard in case I decide to build addition to my house or change layout of my deck.

    Because of that I decided to go with 4" of Insulfrax alone as insulation on top of the dome. The goal is to minimize weight primarily. I have not yet decided if I would go with sheet metal enclosure or wire/stucco over Insulfrax. I have not done the math yet, but thin enoguh sheet metal seems to be lighter than stucco and it will not crack if oven is moved.

    I did a search and have found in several posts that one box of 50 sq ft of Insulfrax should be enough to cover 42" oven. But posts do not specify how many layers you could do with that one box.

    My oven will be 36" internal or about 42" external diameter and I am thinking about putting 4" of Insulfrax.

    How much Insulfrax do I need to cover the oven with 4 one inch layers?

    The calculation I did was (each layer of insulation enlarges surface area needed for the next layer):
    Layer Diameter [in] Surface area [ft^2]
    1. 42" 19.24 sq ft
    2. 44" 21.11 sq ft
    3. 46" 23.08 sq ft
    4. 48" 25.13 sq ft

    Total surface area is 88.56 sq ft, so it means two 50 sq ft boxes should be enough.

    If I do the same calculation for standard 42" internal diameter with 4.5" thick walls - 51" diameter semi-sphere, surface area is then 28.37 sq ft. (or 127.43
    sq ft for all 4 layers combined - three 50 sq ft boxes)

    But this calculation does not account for overlaps and creases - will need more surface area in reality. It also assumes the oven shape is semi-spere. The actual shape will be flatter - will need less surface area in reality.

    Since this is all theory, I need some practical advice on actual amounts of insulation blanket used.


  • #2
    I think you're on target - two boxes will do it.

    My oven is about the same size as yours (35" inside; 43" outside) and a single box of insulfrax covers it nicely; in most places, twice or even three times.

    Use up every square inch of the stuff. You can't put too much on. It's actually pretty easy to work with - docile, easy to form and sticks to itself.

    One piece of advice on cutting it: I found a LONG set of scissors did it nicely. Failing that, saw it carefully with a long carving knife. It will dull the blade of the knife, so make sure it's not a good piece of cutlery.

    Do NOT use a cheap "never needs sharpening" knife.

    It will develop natural folds which you should cut and overlap. The pix should explain how to do it better than my words.
    Attached Files
    There is nothing quite so satisfying as drinking a cold beer, while tending a hot fire, in an oven that you built yourself, and making the best pizza that your friends have ever had.


    • #3
      Great pictures

      Thank you very much for tips and great pictures. I think that they show the procedure so good that they should be incorporated in the oven building pages.

      I have ordered two boxes.