Ice dams are
an issue of preventative
. While a roof is designed to hold snow, unless the roof is perfectly insulated and actively designed to prevent ice dams, they can and will form.
The easiest way to avoid and remove ice dams, is to keep the eave are of your roof (typically the first 4-6' up the roof) free of snow buildup, so any melted water continues off the roof.
Special "snow rakes" are made so a person can safely pull down any snow accumulation while on the ground.
Click here for an example.
If there are any ice dams that have built up, you can use salt to assist in melting an area for the water to runoff (See
link at the top of this email for more details).
Do not chip at an ice dam with a hammer or try to pry it off the roof,
as this will damage the shingles and possibly the structure.