What's best, homebrew or vermiculite/perlite concrete mix?

[adampottebaum]

My eyes hurt from scouring the internet trying to find an answer to this question.
I simply can't afford a 100% firebrick oven, so my options are using homebrew or the vermiculite/perlite concrete mix.
What's best for the interior layer for a wood fired pizza oven? Also, it would be great if any answers to the question had an brief explanation why.
I've seen it done both ways, but I thought the vermiculite/perlite mix was more for insulation, but if I'm not mistaken, the interior layer should be more for retaining heat, not insulating...

I'll be using it occasionally, so probably once a week at most. Pizza most of the time, occasional bread or meat/roast.

Thanks ahead of time for help

Adam

[david s]

Concretes containing perlite or vermiculite become weaker and more insulating the higher the proportion used. For the inner layer it is better to have a strong dense material that is conductive so it will pick up the heat readily and have the ability to store it. If the layer is not strong it will be vulnerable to abrasion damage. It is then important to insulate the inner layer on its outside by insulating it well.