This is typical of ice - damming: the gutters fill with ice, which backs up behind the gutters and creates icicles.
Have you ever seen ice coming from what should be the inside of the house? This occurs once the ice build up on the roof is severe enough to push water back upwards, under the shingles, where it finds its way into the roof structure and eventually out the overhang. Just think what happens when that same water finds its way into the top of your walls...or even across your ceiling!
Roof valleys are often the worst areas for developing ice...and then ice-damming. Why? Well the roof valley funnels all the melt-off water (melted from the heat you paid to put into your house) on your roof into a small area. When all this water hits the cold roof overhang, it freezes, backs up, and can cause serious damage as it pushes up your roofing shingles and eventually finds its way into your house.
This is a great visual example of the heat from within the house melting the roof snow, which in turn is building up at the roof edge as ice and icicles. You can even see the roof rafters in this melting pattern!
"Ice Damming” is when heat that escapes the house melts snow on the roof from underneath. The water runs down to the roof overhang and gutters where it is no longer under the influence of heat from the house and re-freezes. This forms icicles (though not always) and a ridge of ice at the eave. The ridge gets higher and higher, and blocks the water from continued melting or a rain from flowing off the roof. Water puddles behind the ice ridge (dam) and flows up underneath the roof shingles, flooding the attic, raining water down inside the house. This can cause a tremendous amount of water damage inside to drywall, wallpaper, kitchen cabinets, furniture, bookcases, finishes, and flooring.
Ice damming is a result of heat that you paid for, escaping into the vented attic. You are heating your roof, and paying to do so. It means your house is leaking air and under insulated. Chipping ice off the roof is only a temporary reprieve. The permanent solution is to have True Energy Solutions air seal and insulate your home properly. The good news is the repairs pay for themselves over time in the form of lower fuel and electric bills - all while enjoying a more comfortable less drafty home.