Insulating in the base

[LoriS]

Hi Everyone
I'm up to the insulating layer in the base of my oven. Have done my walls and a 80mm layer of concrete and am now trying to decided between another 100mm layer of Vermiculite concrete mix or a vermiculite board. Recently spoke with someone from Thermal Ceramics in Beverley and she suggested the vermiculite board. It's only 25 mm thick but she assures me that the insulative properties are the same as a thick layer of Vermiculite.
Has anyone had experience with any of this?
I'm pretty much over this pizza oven already and I'm not even up to the dome.
Build a pizza oven, my husband says, it will be fun, he says. Yeah right

[ncsmoker]

Re: Insulating in the base

Hi Lori,
I was in the same predicament as you and decided to go with both. My reasoning was it is easy to do this now, but very difficult to change after the oven is in place.

Check out my blog detailing the build. What I did was make a 2" thick mold of the pizza oven and put that into the concrete base. Filled it with vermiculite/concrete and then added the insulating board and cooking tiles.

Has it made a difference? I don't know as I don't have any other reference point. I will tell you that if I fully saturate the oven, I can expect oven temps in the 550 range the next morning for bread.

Hope that helps!

[UtahBeehiver]

Re: Insulating in the base

Lori,

I did a quick comparison of V- board .12 K/M vs CaSi 0.053 K/M board that I used the thermal transfer is a little over twice what CaSi board is and I used 2" of CaSi plus 2" of FoamGlas underneath. I do not think 25mm is enough should be a min of 50mm. Don't scrimp on insulation underneath the floor brick or on the dome. Insulate right and you can cook for 4 days.

[cobblerdave]

Re: Insulating in the base

Gday
Go with the board as long as its in the budget. The biggest advantage its dry!
Up to 1/3 of the V-crete is water and that has to make its way out eventually.
Build on oven on it still wet, and it will take more time to get out
Regards Dave

[GianniFocaccia]

Re: Insulating in the base

For my floor insulation I went with 3.5" of vermicrete and another 2" of ceramic fiber board on top of that. The morning after a 475C pizza session I can barely feel any warmth on the bottom of my cement support slab. (My floor is 2.5" of firebrick underneath 1.25" of soapstone).

The common thought is that 4" of vermicrete has the same insulation value as 2" of board.