You may have noticed long icicles hanging from your gutters and not realize the significance of the damage that may be occurring behind them. Icicles are usually one of the first warning signs of possible ice dams on your roof. This article will explain what ice dams are, how they form and the best methods for removing them safely.
What is an ice dam?

An ice dam is a wall of ice that forms at the edge of the roof, usually at the gutters or soffit. When it forms the water then backs up behind the ice dam and creates a pool of water. This pool of water can leak into your home and cause damage to walls, ceilings, insulation, and other areas
What causes ice dams
Ice dams are usually caused by heavy snowfall and improper ventilation in the attic. This causes warmer areas in your attic then the snow begins to melt, even when the outside temperature is well below freezing. When the accumulated snow on your roof starts melting it runs down your roof underneath the snow until it reaches a "colder" section like the soffit's, valleys or in gutters then it begins to freeze again, this process of thawing and refreezing is what causes an ice dam.
Cleaning the gutters on your home can help prevent ice dams from occurring as quickly but they can still occur if the conditions are right. The gutters will be just as cold as it is outside and in some cases, full of frozen debris. So even if you don't have a soffit for the water to refreeze in, the melted water will most likely refreeze when flowing into the gutters.
How can I remove an existing ice dam?

Properly removing an ice dam can be quite dangerous if you don't know how. In the past some members of the media suggested hiring a contractor to pull the gutters off your home so the whole ice dam process would be solved. This suggestion was well intended but wrong. Contractors that started removing gutters caused significant damage to roofing and guttering systems, then when the snow melted it dropped next to the homes foundation and caused the basements to flood.

WARNING!
Performing ice dam removal is risking severe personal injury and damage to the roof if not done properly. Never walk on a snow covered roof and make sure if your using a ladder you follow the proper safety procedures. I highly suggest contacting professionals with the proper equipment and roofing experience to carry out this job.

Immediate action: Remove snow and ice dam from the roof this will eliminate the main ingredients necessary for the formation of another ice dam and will usually stop the water from coming in within an hour. Using a roof rake and push broom (not water) remove the snow by carefully pulling it down the slope of the roof line. Never pull snow across the roof or it may break off the shingles and other damages. Then carefully chip away a channel through the ice dam so the water will be able to flow through, just make sure you stop when you get close to the roofing. It's not necessary to remove all of the ice in the gutters or the ice dam itself if you have removed the snow from the roof, it will melt when the temperatures rise.
How can I prevent ice dams in the future?

Properly ventilating and insulating the attic is usually the best way to prevent ice dams. The usual recommendation for proper ventilation is 1 square foot of vent for every 150 feet of attic floor area but each climate region may have it's own recommendations so I would suggest contacting a licensed local insulation company near you. If you have small louvered vents at either end of the attic known as gable vents you can either replace them with larger vents, or install an electric vent fan over the inside of them. These special fans usually work on a thermostat and will pull outside air into the attic to keep the temperature inside consistent.
For more information on ice dams and other articles we have written, please see our articles page.