Insulation base

[Ziggy1234]

Hi. First post. Probably a question asked before. I'm in the process of making the oven by Artisan Made Things on Youtube. He makes an insulation base for the oven floor out of vermiculite and Portland cement. Is this strong enough to support the oven? Does anyone know if this mix is supposed to have stones in it like concrete?

Also, I've seen other videos where people use ceramic fibreboard as the insulation base. Artisan does not use this due to concerns about it getting wet. Can anyone advise a preference.

Thanks

[UtahBeehiver]

There are a lot of YT vids that give questionable advise and their goal is "subscriptions" or "likes". Quick answer, no aggregate in p or v crete. If you do some searching on the FB blog you will various options of floor insulation and how to mitigate issues with each type. I suggest you down load the free eplans from Forno Bravo and use read thoroughly. It is a great base (dated) for WFO design and construction.