Believe me Alan, No-one knows chimneys like firemen do, it seems to be here once winter kicks in, the rate of chimney fires go "through the roof" (so to speak).
Bad(damp) wood, lack of chimney cleaning, bits of the flue that have become seperated (after the rivets rusted out).
We've seen it all, usually on a great night of freezing cold rain and a nasty southerly wind off the Antarctic.
