I have two bathrooms with exhausts that are maybe 6 feet apart. I believe they are the same type of exhausts. I need to duct them up through the roof and I'm wondering what I can and cannot do, both to save money and to reduce the number of holes I need to cut in my roof. I've read a few things saying they need to be vented separately, but I'm not 100% clear on this. I guess I'm looking for someone who knows to tell me "Yes, you always need to vent them separately" or "You can vent them together with ducts shaped like an upside-down Y" or "You can only do it if XYZ". If you need more info I'll provide as much as I can.