Perlite grain size, how much is needed

[Steellearning]

I need advice on the recommended perlite grain size for dome insulation.
I'm building a 42 inch dome and would like to know how much is needed for a 4 inch layer? Would 100 ltr be enough?

[stonecutter]

Re: Perlite grain size, how much is needed

Try to get agricultural perlite instead of block fill, which is very fine.

[Steellearning]

Re: Perlite grain size, how much is needed

Try to get agricultural perlite instead of block fill, which is very fine.

The company selling perlite here in Norway wants to know the grain size I would like. I'm thinking around 5 mm but thought I'd better check with the forum to make sure?

[stonecutter]

Re: Perlite grain size, how much is needed

Had to do the old google conversion...yeah, 5mm will be fine.