Ice Dams and You.

Unwanted icicles hanging from the roof are a warning sign of ice dams, which can inflict considerable interior and exterior damage to your home.

WHAT IS AN ICE DAM?

An ice dam is a ridge of ice that builds up along the edge of a roof. To recognize an ice dam, look for a bulge of ice attatched to the eaves or overhang of a roof. There may be icicles hanging off the edge and you may see stains on the siding. The rain gutters may also be overflowing with ice.

The bulge of ice is usually covered with several inches of snow, so you may not see it. Under this build up of frozen snow is the melting snow and ice. If interior damage has already occurred, you will see wet spots on the ceiling or walls or you will see water flowing into the windows.

DAMAGE

Beneath the ice dam, the wood framing is getting wet and possibly rotting. Insulation is becoming soaked, which makes it inefficient. Mildew and mold are growing in hidden spots, causing odors and other problems in your house

Soaked framing and insulation takes a long time to dry out. During that time it will be contributing to wall damage and moisture problems. If left uncorrected, this water can cause serious structural damage.

WHAT CAUSES ICE DAMMING?

Ice dam problems begin when snow accumulates on a roof. Typically, deeper snow and colder temperatures increase the formation of ice dams. Winds from the north or north west usually accompany snowfalls, so more snow is deposited on north and west roof planes. Structures on your roof that trap snow and increase it's depth further increasing the problem areas.

Once snow accumulates on your roof, it acts as insulation. The heat in your attic will cause the underside of your roof to become warm. This in turn melts the snow into a slush/ice/water mixture. This mixture slides under the snow cover and runs down the roof until it meets a colder surface at the overhang. Here is where it refreezes. As more and more slush slides down, the frozen layer gets thicker and thicker.

Unfortunately, you won't notice this because it all takes place under the snow.

Once the ice dam is high enough to overcome the pitch of your roof, water seeps under the asphalt shingles. Once this water penetrates the shingles, it flows under the siding and eaves and leaks through the framing into your home.

WHAT TO DO WHEN THEY OCCUR

If ice dams have already developed on your house, you may be able to wait it out until spring to fix the insulation and ventilation issues your house is having. This is all supposing the water damage isn't significant. You may be able to reach the damaged areas through the attic and catch some of the water. You may also even punch small or large holes in the drywall or plaster to drain the water. This will limit the damage in some cases.

In sever water damage cases, it is possible to chip away the offending ice down to the roof deck to allow it to drain. BE CAREFUL, because removing snow and ice from a pitched roof is dangerous and can cause damage to your asphalt shingles.

Melting the ice with chemicals is an option in emergency situations. Do not however use rock salt.

PROCEED WITH CAUTION

If you have any questions, please consult a professional. If this situation is handled improperly, you can not only create a larger problem for yourself, but you open yourself up to fire hazards. As well, proper ventilation can be tricky to achieve. Attics are not friendly places, and any miscalculated steps could lead to falling through the ceiling.