Ok everyone... I've resigned to building my new hearth with the recommended r-value of 6.6, but I won't be able to start on it right away. I would like to know what you guys think of using the stove without the recommended hearth r-value. I'm not sure what 's under the existing slate hearth, but I figure that if I closely monitor the temperature under and around the stove, then I should be ok. I won't be loading and burning through the night or unattended, and if the hearth gets too warm, I'll shut it down. Any thoughts are appreciated.