Insulation over roof shingles?
I recently moved my family into a home where the original 1924 two-story house was added onto, as near as we can tell, somewhere in the 1980’s. The addition consists of a large living room, bedroom, and bathroom over a tuck under 2 car garage. In looking in the attic of the newer portion, I can see the shingles of a portion of the roof on the original, older part of the home to which the addition was framed directly on to. From outside looking at the rooflines where the old and new meet, there is a valley. From the inside, the portion of the roof I can see from the attic is the angled ceiling and knee wall of my son’s upstairs bedroom. I’m getting ice dams in this valley and I suspect it’s from heat loss through the slanted ceiling of my son’s room. I’m thinking the easiest thing to do to alleviate this is by placing fiberglass batts over the shingles I can see in the attic. What would be the advantages or disadvantages of this? Any ideas or suggestions would be much appreciated. Thank you.
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