You must have seen icicles hanging from roof tops in cold winter months. They look beautiful and picturesque; the stuff fairy tales are made of. They lend an old world charm to the surroundings but there are some not so romantic facts behind them. These dangling icicles lead to the formation ice dams.
How is ice dams formed?
In winter when it is freezing cold outside, you heat your house. The centralized heating makes the ceiling of your house warm. The outer layer of snow, which is in contact with the warm ceiling starts melting. It may also melt because of backing up of the slush which is frozen in the gutters. The melted snow, which is now water, flows slowly under the frozen layer of snow and once it reaches the unheated portion of the roof, it starts freezing. The icicles thus formed at the edges of the roofs do not allow the water to slide off and the water accumulates on the roof. This is called an ice dam.
The ice dams may force the water under the shingles and thus into the attic. The home's ceilings, roof, eave, gutters, insulation and the walls may be damaged. It is a dangerous situation for your house and you must not let this happen. You must take basic precautions to prevent ice dams from forming for the proper protection of your house.
Preventions for ice dams
There are quite a few precautions you can take to prevent ice dams from forming in your house. To begin with you must keep the attic space cold and now allow it to become warm by getting it insulated from the inside. This will not allow the ceiling to become warm and thus snow will not melt and no ice dam will be formed. You may also use high heel trusses for insulating the external potion of the plates and you may also install cardboard baffles so that there is adequate ventilation at the eaves portion. You must facilitate the snow or ice to slide off. For this you need to be sure that the outer most boundaries of the eaves or the gutter drain are always lower than the rest of the slope line. This will be very effective in helping the snow or ice to slide off. You must also keep checking that the gutters are always clean. These are basic and regular maintenance steps you may take to prevent ice dams from forming.
The Canadian Mortgage and House Corporation in its publication has recommended the use of certain materials for the protection of your eaves and preventing ice dams from forming.
It is recommended that a felt saturated with asphalt, which is laid in two piles up to 480mm and then cemented together with type M or S cement is laid on the roof with at least 100mm head. The head and the end laps are then cemented together with the help of lap cement .. It is very effective for preventing ice dam formation.
This information for preventing the ice dams from forming is general in nature and you should follow the instructions of the manufacturers. The manufacturer may also suggest that for additional protection of your roofs and eaves, you use an under-layer underneath the shingles. This will prevent water collected in the ice dams from penetrating into the house. If there is extreme ice in your area then it is also suggested that you extent the eave protective margin beyond 1m as recommended in normal cases. If you take expert help you may be assured of a tension free winter with no formation of ice dams and subsequent harm to your house.