ANCHORAGE - The large amount of snow we’ve had this winter is taking a toll on homes around Anchorage, but it’s not only the weight of snow on your roof that is a danger, it’s the creation of ice dams as well.

Ice dams are formed by continual thawing and refreezing of melting snow. Water often backs up into the roof, getting under the shingles and eventually leaking into the insulation of the house.

Ice dams have been causing damage to homes and businesses in town this winter. One insurance agency said it has received double the amount of claims this year, compared to past years.

Roofing specialist Matt Loewe has been in the business for 22 years and said he can’t remember any winter with this many damaged roofs.

The weight of snow is pushing roofs to their limits, but according to Loewe ice dams should be of equal concern to home owners.

“The biggest problem we are seeing is the amount of snow that's covering up the ridge vents and is not allowing the attic spaces to breathe, and therefore the heat bottles up in the attic space and warms the plywood melting the snow, running off and causing the ice dams that build back beyond what your ice and water shield covers.”

Loewe said ice dams are causing costly damage to many homes, especially when tempatures warm up.

Condensation inside the house can also become a problem.

“So in a nutshell if you'd shoveled that roof off sooner, rather than later, you don't have as much snow up there to melt off and create the ice with.”

It is clear to some insurance agencies that ice dams are taking a toll on homes. “The estimates have just come out, but [there are] 50 percent more claims this year than previous years and the majority of those claims are from ice-damming,” said Justin Goodman of State Farm Insurance.