Thanks guys! I've called out dozens of these over the years, but this is the first time I've ever been challenged about it. I couldn't easily get closer to the flue chase, but I thought I could see everything I need to see about the absent firestopping (not there). When the "Chimney" company said "Firestop is installed at the required 8' - 10' ceiling level since the pipe is not passing thru a second floor, only one firestop is needed." Of course, I was standing on the ceiling joists when taking the photo. Anyway, it just threw me. I'm sticking to my guns on this one!