Repost - Ice Damming - What is it? How to prevent it.
What is Ice Damming
Ice damming is when ice builds up on the edge of the roof. This prevents the melting snow and ice to be able to drain into the gutters. When this happens, it can cause the water to be held behind the ice dam. The water will work its way under the shingles and eventually to the wood underneath. Once water starts leaking in form the roof it can cause damage to ceilings, walls, insulation, and even be a prefect breeding ground for mold.
Water/moisture is the main enemy to any home owner or renter. It can cause massive damage to the structure of the home and create mold that can cause harm to individuals with repertory issues. Not to mention all of the cosmetic issues it causes to the house itself.
What Causes Ice Damming
So, what causes ice damming? Ice damming occurs when heat loss from the home warms the roof just enough to be above freezing. This starts to melt the snow or ice on the roof. This can be from multiple different reasons including but not limited to, not enough insulation in the attic, heat from lights/vents, heat ducts, and holes in the ceilings/walls where warm air can escape into the attic. The thawed water flows down the roof until it hits the roof overhang. The roof over hang is much colder and will freeze the water into ice. This process happens continuously causing the ice to build up creating a dam, trapping water behind it.
How to prevent Ice Damming
Home owners are not defenseless when it comes to preventing ice damming. There are multiple ways to prevent this from happening, some very inexpensive and others that might cost more.
Removing the snow from the roof - The most inexpensive way to prevent ice damming is by removing the snow from the roof. It is pretty self-explanatory, no snow means no water, no water means no ice buildup. By scraping/shoveling the snow off of the roof then it does not give the water the chance to build up enough ice to create an ice dam. This is although very hazardous because the roof becomes very slippery when wet and snow covered which could lead to injury.
Prevent heat loss - Another method to help prevent ice damming is by making sure that heat from the home does not make it up to the attic. This is the main cause for ice damming. To do this you might need to add more insulation, seal small holes from wires, lights, cracks, etc. Anything to prevent the hot air that is suppose to be warming your home from heating the attic. This could include insulating vent pipes, chimneys, plumbing pipes. Not only will this help with ice damming but if you are losing less heat you will spend less on trying to keep the home warm.
Ventilation - Attics need to be well ventilated to help prevent the roof from becoming to warm. Ventilation helps keep the attic and the roof a constant temperature. If heat is coming from the home having the correct ventilation will carry that warm air out through the ventilation and not to the roof.
Source: University of Minnesota Extension
What if it’s too late
If it is too late and you already have ice damming happening on your roof, there are a few solutions. One solution would be to fill a sock with ice melt and throw/place on to the damming area this will slowly melt the ice and allow water that is being held back a way to flow down to the gutters. Another solution is to have a company come out and remove it for you. They usually come with hot water power washer that will melt the ice, or they will get on the roof and remove it with tools by hand.
Heat tape or heated cables can work but can also cause damage to the shingles beneath and most require electricity causing your electric bill to increase. Also, after the water runs off the heat tape it has the chance to refreeze. This is why the goal should be prevention.
Source: Sunshine Contracting
Dealing with and preventing ice dams