I am adding bathroom exhaust fans. The roof caps I have attach directly to the duct (this is not the model I have, but it clearly shows how the duct attaches):
I had a lot of trouble trying to get the flashing slid up beneath the shingles with the duct attached - in fact, at this moment the cap isn't attached to any duct while I come up with a game plan. The main trouble is the length of the duct. This is exaggerated but shows the problem:
Does anyone have any tips or advice on how to do this? It's worth mentioning that I am trying to do this myself, though I am aware that it's normally a two-person job. I can't see how my main problem of not being able to get the flashing slid up between the shingles would be helped with another person, but - I'm listening!