A combination of heavy snowfall this winter and fluctuating temperatures has led to a build up of ice on many homes in Ottawa.

Ice damming occurs when snow melts on the roofs of older homes with poor insulation, only to freeze again in rain gutters.

The ice dam then blocks water from running off the edge of the roof, forcing it to travel along the roof and under shingles and potentially leaking into the home.

Donald Mann with Sanderson Roofing said his company has responded to more than 150 calls in the last week.

Workers remove snow and ice from a rooftop in Ottawa. (CBC)

"The previous two years we hardly did any snow cleaning at all," said Mann. "It was mainly because of the low volume of snow. But this year the temperatures, the large volume of snow coming all at once — it looks like it's going to be a busy winter for snow cleaning."

Homeowner Scott Warden said he spent a good part of his holidays chipping away at ice and snow on his rooftop after a leak developed.

"Now the leak stopped, but we have a nice hole in the ceiling," said Warden, who estimates the repair will cost him about $1,000.

High demand for ice melters

Do-it-your-selfers can try to melt the ice, brush the snow off with a snow rake or get up on a secure ladder and try to do the clearing themselves.

Canadian Tire store manager Scott Hayley said the demand has been high this season for any product that helps clear the ice.

"Every second customer is coming in looking for anything to help them get the snow/ice off their roof," said Hayley.

Mann said for difficult jobs, homeowners should call a professional, but said homeowners who tackles the job themselves should make sure they and their ladders are secure and to use the backside of an axe to shatter the ice and let it fall.

If a professional is called in to do the job, homeowners should make sure the contractor has liability insurance.