Was curious to see how common it is for chimney to be built with sooty repurposed brick. This view is from attic space. We have had the chimney flashing repaired so no more leaking. Previous owners let the leaking go on for a while I think. Anyhow, I see some brick here and there that look like the could be sooty. A couple with a very thin sheen to them ( top left). The picture make them look blacker than they really are, which is more a grey color. I run an insert with an insulated liner. The insulation stops about 18 inches before liner top. The area in photo is about 3 feet or so down from top of liner. I don’t imagine that there’s much to do about this, but wanted to see what you guys thought about this. I’ll put up another picture with view from garage.