How to properly vent attic in windy/snowy areas to avoid snow infiltration

atticventventilation

To ask the other part of question: How bad is it to have wet insulation? that didn't get asked… How do you deal with homes that are in high wind and snowy areas which are susceptible to snow infiltration?

To give some background. Some time after the house was first built (it is about 35 years old), the previous owner had some problems with "leaks" in the house due to snow infiltration through vents in the soffits. It would just pile up in the attic. Later it would get warm, melt and end up as a leak.

The previous owner solved this by closing off the soffits on one side of the house where the wind typically blows the hardest. There are still some vents on the other side. After doing some reading, it seems that this might not be an optimal venting solution (possibly not even code), since a cross ventilation is desirable/required.

Some other notes:

  • Roofing was replaced after about 30 years. At that time there wasn't a sign anywhere of rot due to moisture buildup.
  • House is in NYS. So we get plenty of snow, cold, and wind (50mph isn't crazy).
  • In my time there, I have witness snow piling up in other places, such as coming in the little cracks around/under the garage door. Get a small snow pile inside in the morning.

Best Answer

This is a common problem here in the north country. Normally, soffit vents are fitted with Styrofoam tunnels called "proper vent" that rest on the soffit vents and snug between the rafters and extend apx 3 feet up the roof. Your insulation is then placed around the bottom of the proper vent. Snow rarely will make it all the way up this Styrofoam vent extender. Does your roof have a ridge vent? Most houses that have soffit vents also have a ridge vent. The idea being that the cool air enters at the soffit and warm air exits out the ridge. The only other suggestion I would have is to buy a few rolls of ridge vent filter material. Cut this material into pieces to fit over the exposed soffit vents between each rafter.