Roof venting help

I have a 1.5 story house with a finished room on the upper level, with the angles walls. The roof has no ridgeline venting and there’s no soffit venting. What would be the best way to correct the absence of air flow. Any help would be appreciated.

Cold climate?
I’d go non-vented… but thats just me

I’m in Central Michigan but I am getting alot of moisture in the upstairs along the ceiling.

Are the bathrooms vented properly. Sounds like air sealing is needed.

Check out the links that Barry provided, plenty of good accurate info.

sounds like a indoor humidity issue
what are the sources (occupants, pets, plants, cooking, bathing etc.)?
what can you do to alleviate or remove the source (dehumidify, exhaust, seal and insulate)?

It rained hard in our area and then some kind of water dropping from our roof. Our roof is pure cement. What could be the problem? I don’t see any leak at all.