Warm air rising to the peak of the attic causing snow to melt and flow to the eave.
Ice dam in attic.
The snow layer traps warm beneath the snow which causes it to melt.
The tutorial how to prevent and remove ice dams describes what ice dams are and how you can try to prevent them from forming and damaging your home.
Ice dams can be a real problem in winter.
An ice dam forms when the roof over the attic gets warm enough to melt the underside of the layer of snow on the roof.
This water finds cracks and openings in the exterior roof covering and flows into the attic space.
The dam grows as it is fed by the melting snow above it but it will limit itself to the portions of the roof that average below 32f.
Ice dams usually start or worsen after a heavy snow because of snow s insulating properties.
So the water above backs up behind the ice dam and remains a liquid.
Air must be able to circulate freely under the roof.
Heavy snow coverage on the roof acting as a layer of insulation preventing heat loss.
In a typical home there is a series of vents under the soffits or eaves.
Most attics are designed to take advantage of the fact that heat rises.
Water running down the roof refreezes when it reaches the colder roof edge forming a mound of ice.
If you have a furnace in the.
The best way to prevent ice dams is to ensure that the air in the attic or against the bottom of the roof deck doesn t get too warm.
While stopping a water leak or repairing a washing machine hose down in the basement might be fairly straightforward snow on the roof ice dams and attic condensation are forms of water damage typical to cold climate homes and are a little more complicated and a little trickier to fix.
The water trickles down between the layer of snow and the shingles until it reaches the eave of the roof which stays cold because it extends beyond the side of the house.
When all three of the following conditions occur ice dams can form quickly.
The melt water runs down the length of the roof to the eaves where it refreezes forming a dam and icicles.
Attic ventilation is usually the easiest way to prevent ice damming yet it is the step most often omitted.
Ice dams occur after a heavy snowfall when warm air in the attic causes the roof to warm and the snow to melt.
Ice dams form when heat leaking into attics or roof cavities from the building below or from attic ductwork melts the bottom layer of snow on the roof.
Excessive snow on the roof attic condensation and ice buildup can cause roof damage water damage and personal injury.
Although excess heat moving from the attic through the roof rapidly melts snow once the meltwater touches the cold eaves it quickly freezes and forms an ice dam.
