I am mixing my cement with 3 to 1 cement gravel mix to Portland cement. How much Vermiculite should I add to this mix to optimize the insulating value of the Hearth?
Forum Issues Update
Things are progressing in getting things back in order on the Forum! User avatars should be showing up. Attachment and inline images are in the process of being uploaded. We are still looking for a migration path for the Photoplog gallery. Thank you for your patience!
Vermicilite /Cement ratio