I need some advice on ice dams and icicles we've been having since we added a shed dormer to our Vermont log home. The problem is that because of the height of the ceiling and pitch of the roof, there isn't much space for insulation out towards the wall on the back side. The attic is ventilated with ridge and soffit vents. There are styrofoam baffles which take up some of the limited space towards the outside wall. Basically, I have R19 fiberglass between the ceiling joists, and where ther was space, I ran a second R19 layer crosswise. Since we get water dripping and forming icicles even in 20 degree weather, there either isn't enough insulation, or enough ventillation. Of course, the ridge vent is pretty useless under a foot of snow. Oh, and the chimney runs up through the center of the attic.
I've attached a photo which shows the aproximate level of insulation (red) and the ceiling (green). I'd appraciate any thoughts on whether I should concentrate on better ventilation or insulation. Not enough room for gable vents, especially since the end walls are bearing the weight of the ridge beam.