The snow and ice of winter can wreak havoc to your home. Winter creates a special attic ventilation problem in areas where snowfall and cold temperatures are common occurrences. The problem begins with the formation of ice dams - literally barriers formed of ice - that prevent melting water from running off a roof. Ice dams form when the following conditions exist:

• Warm air accumulates near the peak of an attic. This occurs because most attics experience some heat loss from attic insulation.
  
  
• Lower areas of the roof remain cold, especially just above the eave where temperatures may not be much higher than the ambient outdoor air. If the outdoor temperature is well below freezing, conditions are favorable for the formation of an ice dam.
  
  
• A heavy snow cover accumulates on the roof. Snow not only provides moisture, it also acts as insulation, preventing heat loss from the attic. As a result, temperatures in the attic are typically warmer than when the roof is free of snow.

When all three conditions are met, ice dams form quickly. Heat high in the attic causes snow to melt near the roof peak. The water from the melting snow flows toward the eave area, where colder roof temperatures allow it to freeze. If conditions persist over several days, this re-freezing of snow melt can form an ice dam.

The weight of the dam itself can damage gutter and fascia. When it eventually falls, it can also damage structures or shrubbery below. But the greatest damage occurs when the water pooling inside the dam begins to infiltrate under the shingles. The shingles themselves are damaged if not destroyed, insulation can be soaked, reducing it's effectiveness, and water can seep into exterior and interior wall cavities, leading to structural damage and the deterioration of painted surfaces.

To reduce the possibilities of ice dams or correct any existing problems, there are three steps you can take:

1. Make certain that your attic has proper ventilation. The solution is to equalize temperatures over the entire roof and create a cold roof. You may want to upgrade or add ventilation devices such as ridge vent, attic fans, or static vents to your home. See Goods & Services/Attic Ventilation.

2. Install ice/water underlayment along all eaves and in all valleys. Even the most efficient attic ventilation system may not be enough to eliminate all ice dams. The waterproofing underlayment is a self-adhesive barrier that can minimize and possibly eliminate water infiltration into the building structure. See Goods & Services/Accessories/Waterproof Underlayment.

3. Remove any build-up of snow and ice from your roof as soon as possible. This will eliminate the "dam" that causes the water to back-up.

Just contact us to get help with any of these solutions, or so that we may answer any of your questions.