Published on November 14th, 2012 | by Henri0
Small leak and ice dams persist after re-roofing
Q. We had a new roof put on about two years ago. The old roof was taken down to the bare wood. We had 6 feet of a water shield (whatever the name of that is) put on the eaves. We had a new gutter put on with leaf shield (the wire kind). We had a new bow window put on at the same time.
We get long icicles when there is a lot of snow on the roof. I thought the water shield would stop any leaks into the house when there is an ice jam in the gutters. We still get a comparatively small leak coming into the house. We have been thinking of putting an electric wire snow melter in the gutter, but we have heard that is not the best solution. We have read that insulation, either blown into the eaves, or a thick layer of insulation put into the eaves might help.
The house is a one-story house. The gutter is L-shaped. I wish I could describe it a little better, and I assume you would have some suggestions as to how to prevent the leaks when there is an ice jam. Can you help? ( I am a little too old to do very much by myself.)
A. The waterproofing membrane you had installed under the new shingles should prevent any leakage from water pooling behind any ice dams. However, if a proper flashing was not installed behind the gutter, it sounds to me as if water gets into the soffits of your house between the fascia board and the roof sheathing as the gutter fills with ice. This would account for the small leak.
What should have been done before installing the gutter was to install a bent flashing with its upper leg under the waterproofing membrane and its lower leg over the fascia board before installing the gutter. This way, the open joint between the roof sheathing and the fascia board would have been securely sealed. Correcting the problem will require removing the gutter and pulling up a few inches of the bottom of the membrane to slip the flashing under it. If the membrane cannot be pulled up enough the flashing can be installed on top of it but a new strip of membrane or compatible tape will have to be put over it and the existing membrane to prevent water from getting under the flashing.
I agree that putting an electric heating cable in the gutter is not the best solution; it will not stop the gutter from freezing. To reduce or prevent the incidence of ice dams is another story, however. Do not have any insulation placed or blown into the eaves; it can get wet and it will never dry. Moreover, there is no need for insulation in a cold space; insulation is only helpful to slow down the heat loss between a heated space and a cold one.
Adding insulation in the attic is very helpful but can be difficult to do if the attic is floored and is used for storage. Effective ventilation is also helpful and is best accomplished with a combination of continuous soffit vents and an externally baffled ridge vent as long as there is an uninterrupted airflow between them.by