Hi Howie,
I think you really only need Calcium Aluminate concrete in a commercial oven that is fired 24-hours a day. A large percentage of home ovens are installed using standard concrete (in fact there are installation guides from producers that recommend a simple, standard concrete hearth without any insulation). If you have an easy, local source and it isn't expensive, you could go for the calcium aluminate, as it will last longer (probably long after we are all gone) and perhaps heat up a little faster, but the difference is not worth a lot of effort.
James |