In the grips of a tough winter many homeowners wonder if and when it’s necessary to remove the snow and ice from their roofs. The two main issues to consider are the weight of the snow and ice dams, and the possibility of melting runoff backing up underneath the shingles creating a potential leak problem. If you are concerned about the depth of the snow on your roof you should definitely consider having the snow removed. This is particularly true for lower-sloped (flatter) roofs where drifting may occur. It is also a consideration for the weight of the ice dams at the lower edge of the roof. If ice dams are thick enough the eaves and gutters can sag or give way under the excessive weight leaving you with an expensive repair bill in the spring.
Water pooling behind an ice dam at the lower edge of the roof is also a serious problem and usually isn’t noticed until there is a significant warm-up. Ice has formed very gradually this winter because of the extreme cold and in some cases may extend under the snow several feet up from the lower edge. It may appear to be only a few inches thick but water can pool under the snow at the top edge of the ice, causing problems even for roofs installed with the proper winterizing membrane. Erring on the side of caution is generally recommended. Removing snow and ice can be a dangerous undertaking and is best left to professionals who understand the risks and are equipped to handle all the safety requirements.
None of these suggestions deals with the root cause of ice dam formation. If you think you have excessive ice forming it is probably due to a combination of not enough insulation and a lack of proper ventilation or both. After a winter like this, it may be wise to have a roofing professional evaluate your home for insulation and ventilation to help prevent the formation of ice dams in the future.