I'll try to explain this. My home has two fireplaces, one on the first floor and one on the second. They are pretty much lined up. So, when we have a fire in the bottom(den) fireplace, smoke will come out of the UPPER fireplace box. So, I had the chimney company come and do a cleaning and inspection. So, they went on the roof and came to this conclusion. At the top of the chimney, the CROWN, all the flue are at the same height. Actually, the flues barely stick out of the crown, they are actually almost flush with the crown. They recommended extending the ne chimneys crown(the fireplace we use), and putting a cap on that one and the the other. Thoughts? Advice? THANKS!