Unvented addition roof
Looking for some helpful advice regarding a currently unvented roof assembly.
The house is about 100 years old — there was a small 1-story addition done to the rear of the house. The back porch roof was extended to create a rear bedroom and bathroom. We are currently renovating the bathroom, and noticing that this section of the roof is unvented. There are no soffit vents, and no place for a ridge vent as the roof terminates into the side of the house (just below or at the 2nd floor).
Currently there is a small amount of insulation in the ceiling below the roof. As far as I see it, I can only come up with 1 possible solution — looking for help to know if this is correct.
Since I cannot vent this roof easily, I am looking at unvented options. We just had this section re-shingled so I cannot add foam insulation above the roof deck. Does this only leave me with an option of closed-cell foam in the rafter bays followed by rigid foam underneath to help with thermal bridging? Just seems like a large $$ in closed cell foam.
Thoughts? Sorry if I did not provide a clear enough picture. This is in climate zone 5.
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