1976 Garrison Colonial located in the Northeast. Cold, snowy winters, hot & humid summers. The current attic doesn't have soffit vents and, b/c of a double layer of roofing, there isn't a ridge vent at the top. There is a window on each gable that we leave slightly open (mainly to try to reduce the intense heat in summer). The only insulation that exists are pink insulation bats on the floor of the attic.
We recently added a new addition on to both sides of the existing structure. There is no access from the existing house attic into the new addition attic space. In the new addition - it is completely sealed to the outside. No soffit vents, no ridge vents, no other vents. Insulation was sprayed in at the bays of the roof rafters but no insulation was used on the attic floor separating the attic to the living space.
Which type of attics are correct?
And - for the existing attic of the existing home, should we keep these windows opened so air can circulate through? Or should we try to seal completely? I have noticed moisture building on the underside of the roof in the winter (and the nails from the room shingles that poke through have frost on them).