Ice dam (roof)

An ice dam, by definition, is the excessive formation of ice on the edge of a sloping roof of a house during the winter. The presence of such ice formation on the roof is a symptom of significant problems in the attic components of the building.

Heat losses

The main problem with ice buildup at the edge of the roof is the heat losses (heat loss) from the house to the attic. The heat warms the roof and melts the snow that has accumulated on the roof. Then, the water trickles down the roof and – on arriving in the cold section of the roof that goes beyond the attic – the water freezes and forms an ice dam at the edge of the roof.

The accumulation of ice on the roof is an indicator of the presence of impairments in the attic :

1. Un vapor Absent, incorrectly installed or with holes – in the ceiling of the house – causes the migration of heat from the building to the attic as well as the heating of the roof, the melting of snow and the formation of ice dams.
2. Also, a layer ofisolation inadequate in the attic contributes – with a deficient vapor barrier – to creating a problem of ice dams on the edge of the roof.
3. A bad ventilation in the attic is also a factor that causes the formation of ice on the roof.

The formation of ice on the roof normally indicates the presence of condensation in the attic and mold as well as rotting of the structure. This is because the environment in the attic remains hot and humid due to thermal losses from the house to the attic. In addition, the formation of ice dams causes water infiltration coming from the roof.

Solutions

To solve the problem of ice formation on the roof, you will need:

1. Check the vapor and seal the junctions between the vapor barrier and the devices that pierce the ceiling. In other words, it is necessary to ensure airtightness between the house and the attic;

2. Install a layer ofisolation, with adequate thermal resistance, to minimize heat loss to the attic;

3. Ensure the presence of a system of ventilation adequate (maximum soffits and fans) to ventilate the attic and evacuate hot, humid air to the outside of the house.