I posed this question along with a shot of my chimney cleaning today but it got moved to the old stove forum. So I'll ask it stand alone. I have been burning some slabs the last couple years just because they were very reasonable and close to home. I had a friend tell me that he had heard the bark created more creosote than the wood itself so to be careful burning slabs stand alone a lot. I do not burn them by themselves much, but have on occasion if I get home later in the evening and only have a few hours left before the night load. Has anyone else heard anything to that effect.