Just reciently my whife and I moved into our new colonial house. We have had record breaking freezing temperatures this past week. While putting away the xmas tree, I noticed that the plywood on the north side (front of the house) of the attic roof is saturated with water. In some places, were hardly any sun hits during this season, frost has acumilated on the plywood. What was surprizing was that the south side of the roof(rear)was dry. The first thing popped in my head was ventilation. I inspected the area and found no indication of any of the soffet vents being blocked. However, I did notice the the top ridge(where the 2 roofs meet) appeared to be air tight, capped off by roofing shingles. I asked around in the neighborhood and they don't seem to have the problem. Is this a form of "Ice damming"? Do I need to increase my air flow ?