Last time I burned last week it sounded like backpuffing (later I found out the upstairs windows were open), but it wasn't extreme enough to know if it was or wasn't. So, since the weather is cooling off this weekend, I'm planing on burning this weekend so I wanted to take a quick look at the chimney to make sure all is well. I took off the bottom panel of the chase and i found this - a shim from I have no idea where is way too close to the chimney. I thought I was being over careful, now I'm glad I was. That would have really ruined my burning fun this year - don't think it would take much to set that off.