Started new oven - Vermiculite versus insulboard

[Rivernook]

Hello to all, thanks to Forno Bravo and all the honest postings. My 11 year old son and I have just finished dry stacking the stand for an "as per plan" 42inch Pompei. Great project, pity we need to to sleep!

From some older posts I get the feeling the cement/vermiculite layer offers less insulation than Insulboard? Someone even suggested both for best performance? Cost is not too prohibitive for me. Suggestions welcome.

Looking forward to posting some photos and contributiong something back to the group. All the best.

[dmun]

Re: Started new oven - Vermiculite versus insulboard

Two inches of cal-sil board or four inches of vermiculite concrete are what's called for in the plans. The high tech board is a slightly better insulator, thinner, and easier to install. I just placed my boards on the wet concrete of the slab and put my floor bricks directly on top of that. You can add more, or do both, at your choice, but either one should do the job.

Welcome. We look forward to your photos.

[Rivernook]

Re: Started new oven - Vermiculite versus insulboard

Thanks for the advice. I have found an Aust. supplier of Cal- silicate board so think I will go for that option.

As an aside, I have found this great fun so far - also fantastic bonding with my young son!! He did a lot of the stacking blocks today, and got almost as much pleasure in getting it perfectly level and square as me. During slab pour he also learnt to move fast and/or steer clear of dad when cement mixer breaks down!! Bye for now.

[Irv Mac Dowell]

Re: Started new oven - Vermiculite versus insulboard

As I stated in an earlier thread, I had trouble with moisture wicking from the concrete into the board when I placed it on wet concrete. The concrete underneath was essentially dry in minutes. I rewet it and reinstalled the board, but I hope all's well underneath. I think the instructions in the installation manual aren't clear about board installation. It appears from the pictures and instructions that the board should be laid in wet concrete, but now I think that's a mistake.

Best regards,

Irv