Lawton Insurance Agency

Preventing Winter Damage To Your Home:   Ice Dams
Ice DamsFebruary 2014
In This Issue
Ice Dams
What Causes Ice Dams?
Prevention & What Not To Do?
Water Damage
Lawton Insurance Agency Inc
 
225 E Chestnut St
Mifflinburg PA 17844
570-966-3145
icicles Ice Dams
We see claims of all different kinds throughout the year, but among homeowners, one of the most persistent wintertime complaints is ice-dam damage.  The sight is familiar in our area, a house with snow drifts on the roof and a mass of ice at the eaves ends up with water damage in its attic, walls, and ceilings.  We thought it would be important to let our policyholders know what they can do to prevent ice dams or what to do if it does occur. 
 ice dam2What Causes Ice Dams?
Ice dams occur on sloping roofs in climates with freezing temperatures.  When the temperature in your attic is above freezing, it causes snow on the roof to melt and run down the sloping roof.  When the snowmelt runs down the roof and hits the colder eaves, it refreezes.
If this cycle repeats over several days, the freezing snowmelt builds up and forms a dam of ice, behind which water ponds.  The ponding water can back up under the roof covering and leak into the attic or along exterior walls. The right weather conditions for ice dams is usually when outside air temperatures are in the low 20s (F) for several days with several inches of snow on the roof.  Research shows keeping the attic air temperature below freezing when the outside air temperature is in the low 20s can reduce the occurrence of ice dams.  Research has shown sun exposure in the winter has little effect on attic air temperature.  Warm air from living spaces below penetrating into the attic is usually the culprit in the formation of ice dams.
 Prevention of Ice Dams & What Not to Do 
- Prevent warm, moist air in living spaces from infiltrating into the attic with a good air barrier and appropriate water vapor control at the base of the attic.
- Provide good attic ventilation to replace warm air in the attic with cold outside air.
- Provide adequate attic insulation to reduce the transmission of heat into the attic from living spaces below.
- Consult a professional for the best way to avoid ice dams and water damage in your home.
- Do not routinely remove snow from the roof.  It will likely lead to shingle damage.
- Do not attempt to "chip away" the ice of an ice dam.  It will likely lead to shingle damage.
- Do not use salt or calcium chloride to melt snow on roof.  These chemicals are very corrosive and can shorten the life of metal gutters, downspouts and flashings.
 If Ice Dams Are Causing Water Damage
The following are short term fixes.  In order to avoid the same problem in the future, a qualified contractor should assess the amount of attic insulation and attic ventilation, and look for holes in the air barrier between the living spaces and the attic.
- If you see water staining at an exterior wall or ceiling where there is snow on the roof above it, act quickly to avoid extensive damage.
- Hire a contractor to carefully remove most of the snow from the roof above the ice dam. 
- Have the contractor create one or two grooves in the ice dam to allow the ponding of water to drain off.
- Call your insurance agent to report and try to prevent any further damage. Your deductible will apply to any damage.
We realize its sometimes hard to prevent ice dams from happening.  But please don't hesitate to call us if damage is caused to your home.  We appreciate any prevention taken to reduce the liklihood of a claim.  Thanks for your business!