what grade of vermiculite

[anderstim]

What is the grade of vermiculite that is best for insulating around/above the dome

[azatty]

Re: what grade of vermiculite

Coarse to medium. You're trying to create air space within the material to trap the heat, so powdery stuff isn't preferred.

[david s]

Re: what grade of vermiculite

Coarse to medium. You're trying to create air space within the material to trap the heat, so powdery stuff isn't preferred.

Yes that's true, you don't want powdery, but the fine vermiculite makes a more workable mix although it takes more water. I doubt whether ther is any measurable difference between fine med or coarse in the final product, after all a bucket of small marbles weighs the same as a bucket of large marbles. The spaces maybe bigger but the volume of the spaces is the same. Try 50% perlite 50% vermiculite it makes a good workable mix with minimal cement needed to hold it together

[azatty]

Re: what grade of vermiculite

I figured you are using it for enclosure filling. But if you're doing an igloo, I'd go with david's suggestion.

[david s]

Re: what grade of vermiculite

I figured you are using it for enclosure filling. But if you're doing an igloo, I'd go with david's suggestion.

Yeah,sorry, I was assuming you we're doing an igloo. If doing an enclosure go with azatty's advice. Probably less compaction with the coarse stuff.

[adypearson]

Re: what grade of vermiculite

I am also search for the grade required for making an insulated hearth, but I can only seem to get my hands on Perlite ore down in New Zealnd.