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. The water that backs up behind the dam can leak into a home and cause damage to walls, ceilings, insulation and other areas.
Long- and short-term ice dam control
Ice dams can be prevented by controlling the heat loss from the home.
Short-term action
Remove snow from the roof. This eliminates one of the ingredients necessary for the formation of an ice dam.
- A “roof rake” and push broom can be used to remove snow, but may damage the roofing materials.
- In an emergency situation where water is flowing into the house structure, making channels through the ice dam allows the water behind the dam to drain off the roof.
- Hosing with tap water on a warm day will do this job.
- Work upward from the lower edge of the dam.
- The channel will become ineffective within days and is only a temporary solution to ice dam damage.
Long-term action
- First, make the ceiling air tight so no warm, moist air can flow from the house into the attic space.
- After sealing air leakage paths between the house and attic space, consider increasing the ceiling or roof insulation to cut down on heat loss by conduction.
Warning
- Anyone on the roof during the winter or performing work on the roof from below risks injury and may cause damage to the roof and house.
- It is important to contact professionals to carry out this job.
- Whenever a house is tightened up, ventilation systems, exhausting devices and combustion devices must have enough air to operate safely and effectively.