Perlite to concrete ratio?

[KEmerson]

Hello all,
Can anyone tell me what the ratio of perlite to concrete is for a hearth? I did mine a few years ago and simply can't remember. I know it's more perlite/ less concrete. 8:1? 5:1? Ok, I'm stabbing in the dark.
Thanks
Kim

[stonecutter]

Re: Perlite to concrete ratio?

5:1 - 8:1 is a good range. More Portland = lower insulating properties.

[KEmerson]

Re: Perlite to concrete ratio?

Thanks. I was working from memory and the big take from this is knowing that there's still some memory to work from.
Kim