Newbie with Material question

[Brad H]

Hey all I have been reading in older posts about building materials (insulating) What sub fourm would be the best place for this type of question? Oh, also I am in the process of building a oven using a form and poured cement type mixture.

[david s]

At what stage of the process of building are you at? It is best to have both a design and method of building before commencing.
There are many types of insulation that can be used with varying qualities, accessibility and price.
The "finding building materials"section is probably the go to section you're after.

[Brad H]

I am in the gathering of materials stage. My plan is to use a form and add a perlite/vermiculite type mixture to cover for the structure and heat retention. I work in the Redi mix concrete industry and I am looking into a light weight rock we use to replace the perlite material. The light weight rock is made up of super heated clay and has a appearance similar to pumice stone. it is full of voids that make it lighter than other aggregates that are used in regular redi mix applications.

[UtahBeehiver]

Just to make sure, you are talking about what to place over the main dome? Perlite/portland is for insulating purposes only and needs to go over a dense refractory dome. The dense refractory provides the thermal mass and the perlite/portland provides the insulation for the dense refractory dome (this can be home brew or commercial). Don't fall for those YouTube videos showing perlite/portland main as the main dome material. It is not in you best interest.