Is this house breathing?

Inspected a house yesterday and while I was on the roof, which was 15 years old and in great condition, I noticed that there wasn’t any roof vents. There were soffit vents around the eaves, but no roof vents, gable vents, etc. The attic was in excellent condition, with no venting evident on the original plywood sheathing ( I thought maybe they were covered up for some reason during a re-roof). Anyway, I was wondering, can anyone give me some helpful insight? I’ve seen many house with inaddequate/blocked insulation with the normal telltales, however, this roof & attic were in great shape. A sealed system. like newer crawls?
BTW, the house was built in '59 and there was only insulation on the floor of the attic. Any help would be much appreciated.

Enjoy the weekend! It’s 8:15am here in Ohio, that’s plenty of time to help a brother out, before football starts!

Built in '59, I can say it’s probably not a sealed system. :stuck_out_tongue: The original attic insulation was probably only 2-3" deep, with no vapor barrier, or just the paper backed batts. Sometimes in that era the soffits are sheathed and stuccoed over as well with just a vent or two along each wall.
So this is just my theory: the attic is like a conditioned space, kept warm and dry by the heat from downstairs, with a bit of air leaking in and out through various cracks and the vents at the eaves. It is like having another floor with a vaulted ceiling. That all changes when we add more insulation and try to stop heating the attic with the living space. Now the underside of the sheathing cools enough at night for moisture to condense and all the rest of it.

John Kogel