Ice Melting Roof Leak
In general the steeper your roof the more thick an ice dam would have to be to cause damage.
Ice melting roof leak. Fill pantyhose with sidewalk salt to break up ice at the edge of the roof. An ice dam forms when the roof over the attic gets warm enough to melt the underside of the layer of snow on the roof. The water that backs up behind the dam can leak into a home and cause damage to walls ceilings insulation and other areas. This type of leak is not workmanship related and is not covered under labour warranties.
When your roof heats up and melts the bottom layer of snow or ice the water leaks down to the edge of your roof and freezes again creating an ice dam. Not gutters or the lack thereof not frozen gutters not low pitched roofs. They will often be behind ice dams on the roof. Roof leaks are obviously a big problem in any house but knowing the correlation between melting snow and roof leaks can help you to prevent one of the major problems that many houses face.
Note where the leaks are so you can look for them after the weather warms up. Sometimes this backed up water can travel as much as 5 10 feet under the shingles. The cold air helps freeze the melting ice back up. As more snow melts more water runs down the roof and meets the ice build up or dam and backs up under the shingles and into the attic.
There is a single cause for ice dams and the subsequent leaks. Providing a drainage path for such water accumulations is one way to stop ice dam leaks dead in their tracks. This backs the water up under your shingles allowing it to run down the exterior sheathing or interior walls and ceilings sometimes for great perplexing distances. As even more water runs down it now has nowhere to go so it backs up under the shingles and leaks into your roof.
The melting snow is often caused by warm moist air escaping into the attic due to a poor vapour barrier. Moisture entering the home from ice dams can lead to the growth of mold and mildew. Dripping water or water stains make them recognizable. For this discussion an ice dam is a place where you have melted snow that freezes on the roof which eventually builds up and blocks the downward flow of other melting snow.
The water trickles down between the layer of snow and the shingles until it reaches the eave of the roof which stays cold because it extends beyond the side of the house. An ice dam is a ridge of ice that forms at the edge of a roof and prevents melting snow water from draining off the roof.