Ice dams are simply ridges of ice that form at the edge of a home’s roof and prevent the melting snow and/or water from draining off the roof. This water, if left undrained, can cause leaks in your home’s roof, ceilings, walls, insulation and other problems.
A number of things can cause ice dams, including the loss of heat from your home, snow cover on your roof, and the outside temperatures. In order for ice dams to form, there typically must be snow cover on the roof of your home. At the same time, the higher areas of your roof’s outside surface are normally above freezing, while the lower surfaces are below freezing. This typically happens when the temperature outside is lower than freezing or 32 degrees Fahrenheit. When the temperatures at the higher levels of your roof reach above freezing, they begin to melt. As the water from this melting snow runs down the roof and reaches the lower portions of your roof (that are below freezing) it re-freezes. This causes an ice dam. The dam will grow as more water runs down the roof from the melting snow but will typically limit itself to those areas of the roof that remain below the freezing point. The water that has become trapped above the ice dam will remain unfrozen, finding cracks and openings in the roof and potentially causing water damage in the ceilings, insulation, and walls of your home.
It is possible to prevent and/or stop ice dams before they cause damage to the roof and interior of your home. In order to prevent ice dams completely, you must control the heat loss from your home. This can be done by checking your ceilings to ensure that they are well insulated and that no heat is escaping through the higher areas of your roof.
If you currently have ice dams, they can be removed before any damage is done. You must first remove the snow from the roof. This will eliminate the water that turns into ice when it melts and refreezes. Brooms or roof rakes can be used to remove the snow from roofs but keep in mind that you could damage your roof if you incorrectly use a roof rake. In emergency situations where the melted snow is flowing into your home, you can create channels to allow the ice dams to let the water drain off the roof. Taking a water hose and applying warm water on a day in which temperatures are above freezing will create the channels and allow the melted water to flow off your roof, preventing a further ice build up and keeping your interior safe from water damage. Keep in mind however that these channels will only work for a few days so you should remove the ice dams from your home as soon as possible.