I haven't personally put the tape on the pipe for the Temco yet...but my husband swears it's reading 8 1/2". Is there a size other than 8", or are 8" pipes not really 8" (like dimentional lumber, it isn't really 2x4)? Could it be he just randomly chose the "flared" (bottom) side? We wanted to get the ceiling kit and put it back in so we could use the sunroom during the winter...but first we have to figure this part out. It seems no one locally has a kit for 8" pipe (6" and the 3" pellet are common) so we can't just take a section of the single wall we have up to a place and see if it all fits together. We have some single wall black pipe already, but no through the ceiling or anything above. The other option is ventfree logs, which I'm not really a fan of...wood is cheaper than propane, it can burn the pieces that are a little longer than the Lopi can handle, there's no good spot for a tank, wood looks better...and it's kinda big so if we're going with gas I'd rather sell it and buy a smaller unit that takes less space. Plus there's the fact that it's normally un unheated room so I bet ANY moisture the logs would release would fog up/frost up the windows with a quickness, so it wouldn't be worth bothering with anyway.