Hacking away at ice dams with a hammer, chisel, or shovel is bad for your roofing—and dangerous for you. And throwing salt on them will do more to harm to your plantings than to the ice. Short of praying for warm weather, here are stop-gap measures we recommend.
Take a box fan into the attic and aim it at the underside of the roof where water is actively leaking in. This targeted dose of cold air will freeze the water in its tracks. "You'll stop the leak in a matter of minutes," says TOH
general contractor Tom Silva.
For more advice from Tom, see Stopping Ice Dams