Dave Klatt, Guest Column

Nothing says winter to many people like heavy snow blankets and icicles hanging from the roof of their homes. But, the snow and icicles present a subtle danger, ice dams.

After several days of melting-freezing cycles, it’s common for the melted snow and ice to work up under the roof shingles until water enters the attic and eventually does damage to the ceilings, walls and contents. Ice dams that go unnoticed for an extended period of time can significantly damage the home and its contents.

The right weather conditions for ice dams is usually when outside air temperatures are below freezing 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 risk of ice dams.

There is no guarantee an ice dam won’t damage your home, but you can consider these steps in trying to avoid ice dams from forming in the first place:

• Before winter, clean leaves and debris from gutters and downspouts.

• Eliminate any heat sources in unfinished attics. Ductwork in the attic should be sealed and insulated.

• Prevent warm, moist air in living spaces from entering unfinished attics with a good air barrier and appropriate water vapor control at the base of the attic.

• Do not install mechanical equipment or water heaters in attics, especially in cold climates.

• Evaluate the insulation and ventilation in your attic. Most experts agree the R-value of attic insulation should be at least R-30 (R-38 is preferable in northern climates).

• Provide good attic ventilation to replace warm air in unfinished attics with cold outside air.

• Make every effort to keep snow on your roof to a minimum. Long-handled devices on the market called roof rakes let you stand on the ground and pull the snow off the roof. Remember to stand clear of the falling snow and ice.

• Make sure a secondary moisture barrier is installed if your roof covering is going to be replaced in the near future.

Ice dams can be damaging, but a few, simple steps can reduce the possibility of build-up. Talk with an insurance professional for more information on these and other home safety tips.