Almost everyone here in New England knows why an ice dam leak occurs, so I won’t go into great detail about the anatomy of an ice dam leak. However, let me give you, reader, a brief summary to jog your memory. Snow accumulates on the roof. The exterior wall of the house at the eaves loses heat, usually due to poor insulation. Heat rises through the roof and begins to melt the snow. The outside temperature freezes the melt and rises through the roof under the shingles. The water is now under the shingles and reaches the house usually along the interior wall at the intersection of the roof with the eaves.
Call your contractor or roofer and they will tell you that the roof was not installed properly. Some will tell you that the insulation needs to be addressed or that the ventilation is not working properly. It can be fixed? Yes. Everything can be arranged. In some cases, you will want to rebuild your roof to include the proper overhangs and proper soffit vents with the correct ratio of ridge vents or gable vents to create air convection on the roof to keep it cool. Someone might even tell you to build a cold roof. There are always heating cables that you can run to the ceiling, or maybe you could use a metal skirt. That’s a 2-foot metal edging around the perimeter of the roof in the hopes that the ice and snow will slide off instead of getting damaged. What typically happens with this solution is that the ice dam forms higher on the roof, just above the newly installed “solution”, which can further exacerbate the problem.
Some of these solutions may be helpful in correcting the problem. But over time, with an asphalt roof, one will end up with more ice dams even if the ventilation was corrected.