I have a 12’x44’ Park Model with cathedral ceilings throughout. Roof is 4/12 pitch. I am in the process of adding a 12’x12’ addition off of the living room area. The addition section will not have a cathedral ceiling. The new addition roof will tie into the existing park model roof. I plan on stripping off a section of shingles on the park model, then adding valley nailer boards on top of the existing plywood sheeting for my rafters, then framing the new roof over top of the existing roof.
My question is: Because the soffits on one side of the existing roof will be blocked by the ceiling joist of the new addition, will I have a ventilation problem in the cathedral ceiling section of the park model roof?