Ventilation Louvres

Soffit vents not connected to ridge vents?

I have a house with a gable roof where the second floor is a loft. There are triangular crawlspaces to the sides of the loft space and a triangular attic space above the ceiling. There is an access door to the northern crawlspace and no access to the attic space. The crawlspaces to the sides are not connected to the attic, but there are soffit vents and ridge vents. Since the crawlspaces are not connected to the attic there is no airflow from the soffit vents to the ridge vents. The problem is that in the winter I often get strong, cold north winds which send lots of cold air into the crawlspace via the soffit vents, and then directly into the house via the crawlspace access door and most of the electrical outlets on that side of the house. What is the correct way to fix this? Should the crawlspace have gable vents? This would allow air to flow up the soffit vents and then out through the gable vents. I’d still want to seal the leaks into the living spaces, but hopefully the added vents would reduce the air pressure in the crawlspace so less air would be forced into the house.

Public Comments

1. Yes, usually they leave a space above the top of the gable end so that part of the roof can vent. It may be hard to see, but should provide a small airspace there. If you seal the soffits, you will solve your winter problem, but could create heat build-up in the summer.
2. I'm guessing your attic was converted to a loft. You are correct: warm air moves upward, so for attic ventilation to work, cool air has to come in soffit vents and go out the ridge vent. I'm assuming the loft ceiling/kneewalls are insulated. For the attic space, I'd add a louver to each gable end. Not ideal, but it should work. For the two spaces between what I'd call the kneewalls and the soffit: you could consider the rectangular roof vents. Whatever you do: understand attic ventilation works in winter to prevent escaping heat from partially melting snow on the roof and creating ice dams which create leaks. I Don't know what your climate is. Also, insulate the knee walls and above the ceiling. Buy foam gaskets for electrical outlets and light switches.
3. Tom W is right on but there's one more thing you should know. Don't block the soffit vents. They are necessary in both summer and winter. So, the idea of adding vents is good logic.