I live in central Canada, where snow and cold weather are plentiful. There is a west facing wall on my home that is particularly susceptible to an ice dam, Im trying to fix the cause of this problem not just the symptoms.
The interior space below this attic is a vaulted roof, so access is near impossible. I can try to add some insulation, but Im fairly certain my problem is poor ventilation. So if anyone has any tips on approving ventilation, Id appreciate it.
Please refer to my attached drawing, but here is my issue. I have a west facing wall with a jut out for patio doors. This jut is all the way to the eave's edge, so as a consequence there are no soffits above this jut out. There are soffits with soffit vents in the other area of this wall where these is no jut out. The area above this jut out has no ventilation intake at all, this is also the area where I get a very large ice dam every winter. Im fairly sure that the lack of adequate ventilation above this jut out is whats causing my ice problem, I just need a way to fix it preferably without destroying my roof in the process.
Ive looked into adding Smart Vent in this location above the jut. This would require some roof destruction though, plus Im unclear as to whether I could only do this on a portion of the roof and not the entire width. Im also in Canada, and I cant seem to buy Smart Vent in Canada?
Im wondering if a power vent on the top of the roof would function to draw more air into the existing soffit vents, and by extension improve ventilation above that wall jut out?
Does the vaulted ceiling have insulation baffles in it? If there's no soffit its doubtful they would have put baffles in. If there's no baffles, add them before putting the smart vent in. Depending on the depth of the rafter bays you may have problems doing this, however.
You can buy a similar product at Spar marathon, they may even carry smart vent itself, I don't recall. They come in 4' sections and you can install it in just one area.