Phatty said:
>
.i have ice dams again this year after every snow fall i rake the roof
never had this problem till i addad a second layer of insulation 3 years ago
i made sure the eves were not covered with
insulation this house is 100 plus years old has blown in insulation in the walls ive seen pics on here of pink foam between
the joists in the attic is this the easiest fix ?
Was flabbergasted to read this post. Our old house in the Utah Rocky Mountains at 7200 ft gets on average 250 inches of snow and some homes here do suffer from ice dam problems. Contrary to what you wrote, we blame it on insufficient insulation, rather than on adding insulation!
As I read on, it soon became clear that you must indeed have so little insulation that you are better off raking everything off after a storm whereas we try to leave all the snow on the roof for its insulating value (unless some porches or other roof overhangs cannot bear the weight anymore in very heavy (up to 400 inches) snow years).
A very experienced roofer in our area was once asked (on a local forum) what the best way was to fight ice dams: heating tape or aluminum roof skirts? He laughed and said: "If you do have ice dams your insulation is faulty, particularly in the eaves. You should first try to improve THAT!"
Nonetheless, we did sometimes get caught with unexpected insulation loss problems; often as a result of squirrels or even raccoons getting into attics or tunneling into cathedral ceilings and once we were too far into the winter season it is usually was too late in the season to repair things right away.
Just as mentioned by one of the responders; as a temporary solution we would put the hot water hose on it to cut some channels. Others might put in electric heating tape. The worst method, of course, is to take an ax to it (e.g. from one of the upper decks) and then having to repair the roof damage in spring.
Why am I bringing all this up here, although it is not very pertinent to your problem?
Well, I imagine some people with newer, well-insulated roofs might read this thread and perhaps think they should always rake off the snow and never add extra insulation........
In short: if you have excellent insulation and your roof is strong enough: don't touch anything. If you still get a few ice dams, just deal with it carefully (e.g. with hot water and/or heating tape) and plan to check and improve your insulation before the next winter. Snow has very nice insulating properties.
However, if the snow is melting in many spots, other than just over the eaves, the situation may indeed be far enough out of control to make raking advisable. It is a little bit like being caught in a swampy stretch of forest; are you better off trying to make it accross or is it smarter to retrace your steps?? The worst thing is to be caught in the middle.
Henk