There are Many Quick-Fixes for Ice Dam Formation, but Only One Cure
Ice dams form on roof edges under certain winter conditions, especially when snow melts and then refreezes. Ice dams can damage your roof and, in turn, your roof structure and home, including gutters and downspouts.
In New England, ice dams are a common sight, and most people cherish a few icicles hanging from their eaves come Christmastime. However, avoiding ice dams should be a priority, or at least minimizing the risk of damage if their formation is unavoidable.
The cure for ice dams is simple:
- Better Sealing
- Adequate Insulation
- Attic and Eave Venting
Why Do Ice Dams Form in the First Place?
Ice dams form when the roof heats up and melts the underside of the snow mass that has accumulated on the roof. Water flows to the roof’s eaves, which is a colder part of the roof because it extends beyond the outer wall of the home. The water then freezes, and eventually accumulates into a lump or mound of ice.
Ice will accumulate faster if the pitch of the roof is flatter, and gutters may also trap snow causing large buildups of ice, eventually forming an ice dam.
Why Should I Worry about Ice Dams?
To put it plainly: Ice dams cause damage, which could lead to expensive repairs or even necessitate roof replacement.
If an ice dam grows large enough, water can back up and seep beneath the shingles. This water may then leak into insulation, through the roofs support structure and ceiling or through walls, destroying sheet rock and paint. If an ice dam (or icicle) breaks free of the roof, it can damage anything it falls on, including pets and people. Additionally, even a small amount of consistent wetness can cause black mold or mildew to form on interior structures, affecting the air your family breathes.
You can deal with an ice dam in two ways: Either attack an already existing ice dam, or prevent it from forming in the first place.
Managing an Existing Ice Dam
If you already have an ice dam on your home to deal with, follow these steps to remedy the problem:
Remove the Ice Dam – This should be done carefully, by breaking the ice dam into small chunks. This is best accomplished by using a blunt instrument like a rubber hammer, not a sharp tool, as this may damage your shingles.
Even if you’re extremely cautious, you could still damage the shingles. Also, this work can be quite dangerous, especially if the ice dam is large or in a hard-to-reach area. For this reason, we recommend hiring a professional.
Clean Your Gutters and Downspouts – Again, this is potentially dangerous work because you will have to use a ladder, and could damage your gutters and spouts while cleaning them.
Melt the Ice Dam using Calcium Chloride – Don’t use the rock salt you use on your sidewalks and driveways, as this substance will damage metal, paint, and any plants that live beneath the overhang. A good method for melting a thick hump of ice is to fill a leg from an old pair of stockings with calcium chloride, then tie it off, and lay it on the ice dam. It will slowly melt through the ice and clear a trough for water to flow.
Preventing Ice Dams Before They Form
Eliminating snow before it thaws and refreezes is the best way to prevent ice dam formation. You can use a snow rake, broom, or plastic shovel to clear snow immediately after it falls. If you’re using a snow rake from below, you could end up burying yourself in snow, and pushing from above could cause you to fall off of your roof, so you need to exercise extreme caution.
A better bet is to hire someone to do the job for you.
If ice dam formation is a real problem, you may consider replacing your shingled roof with another variety of roof more suited to heavy, consistent snowfall. Metal and standing seam roofs are fine choices. Another solution is to replace the bottom sections of your roofs, just above the eaves, with a wide metal drip edge. You should also install a water-repelling membrane under any new roof you choose.
The Real Cure for Ice Dams
While these methods may remedy the symptoms of ice dam formation, there is only one way to cure the issue:
- Seal all areas where warm air from the structure’s interior into spaces beneath the roof sheathing
- Prevent convection and conduction of heat through the ceiling by properly insulating the living space
- Prevent heat trapping by venting the space between the roof sheathing and your insulation
Not only does this solve ice dam formation issues, but also cures problems of heat loss from the home. The money you spend to prevent ice dam formation will be more than paid for by your overall energy savings. You will also feel more comfortable and warmer during those cold winter nights.