The Mystery of Roof Edge Assembly
Thank you. My goal is to stop air infiltration into the subfloor between the floor on this west side where the prevailing winds hit. Although, for a while, there will still be opportunities for the wind to find a crack elsewhere.
The roof deck on this 1950's house is 1x6 plank on rafters, with 1/4-inch spacing. Before I bought it, I thoroughly inspected it. All the planking is in good condition. The roof was immediately stripped and new shingles were installed because of a leak on the east side that had been left unattended during a foreclosure.
As you noticed, there seems to have been some moisture infiltration on this west side. It's not too bad, and the rafters are all in good shape. However, I primed all the exposed rafter tails. I suspect that the combination of the house's poor envelope, the adjacent finished attic, the western exposure, nearby trees, and the kitchen below, contributed to the moisture problem. A lot can happen in 60 years.