The Roof Ice Dam
Ice dams are a pervasive and damaging winter roofing problem caused by poor roof ventilation and a warm attic space. Left untreated, ice dams can cause serious damage to your roof, gutters, paint, insulation, drywall, structure and even contribute to mold.
Ice dams form when melting snow on a roof runs off and refreezes at the edge of a roof. This condition occurs when the snow is melted by a warm roof, creating water running between the snow and the warm roof surface, then freezing and turning to ice when it gets past the exterior wall and hits a cold unheated roof edge or gutter. As the bottom of the snow pack continues to melt, water continues to flow down the roof surface until it hits the ice, thereby creating a larger and larger ice dam.
As mentioned earlier, when roof snow is melted by a warm attic space, the water runs between the snow and the warm roof surface. The water then freezes and turns to ice when it gets past the exterior wall and hits a cold unheated roof edge or gutter. The ice dam grows as the snow pack continues to melt, and as water continues to flow down the roof surface. When the water flow hits the ice it creates a larger and larger ice dam.
Ice Dam Damage
If this situation continues, the ice can work its way back up the roof edge, get under shingles, melt and leak into the exterior wall, home or attic. Damage from ice dams may not be readily apparent. As the ice melts and possibly drips into the wall or attic, insulation can be become wet and lose its ability to perform. In some cases if the right temperature and humidity exist, mold may begin to grow in the attic. Often paint will peel or blister weeks or months after the ice dam has melted as moisture from the leak in the wall or ceiling cavities tries to leave and pushes outward.
Since ice dams are the furthest things from our minds in the summer, most people battle ice dams in the winter. Unfortunately your options at this point are limited, at least the safe ones. But there are still some effective actions you can take.
Here are some recommendations on how to beat ice dams in the winter:
Act fast with a roof rake during a heavy snow: As I mentioned earlier, ice dams happen quickly after a heavy snow because of the insulating properties of snow. If you can get out and rake your roof with a special tool called a roof rake to remove at least the lower 4 feet of snow from the roof edge, you’ll do a lot to prevent the ice dams from even forming. A roof rake is like a shovel that is turned on its side so that you can pull snow off the roof toward you. It has a long handle about 16 to 21 feet long, and is safer than many other approaches since you use the tool from the ground, not on a ladder.
Calcium chloride or ice melt product: If you have an ice dam forming, one action you can take is to put a calcium chloride or similar product on the ice. (Forget any urban legends you may have heard about putting salt in pantyhose, it does not work well, takes a lot more salt and results in the pantyhose ripping apart). When you put the calcium chloride directly on the ice, be careful if you are on a ladder, icy conditions and ladder usage are not recommended so please be careful.
Professional ice dam removal: If you end up with an ice dam and need it removed, you always have the ultimate tool in a toolbox,your checkbook. There are professional companies available that are insured and will remove your ice dam using professional equipment such as high pressure steam. Although this approach may cost a few hundred dollars, the prevention of damage to your home may be significant.
Potential Repair Methods I Do NOT Recommend:
Some tools and approaches to ice dam removal are often discussed but are also very dangerous. I do not recommend any of these approaches because of risk of damage to your life and your home. Please do not try to remove an ice dam with any of these approaches. THEY ARE NOT SAFE!
· Hatchet or axe
· Ice pick or screwdriver
· Propane torch or heat gun
· Hammer and chisel
· Duct tape (OK, well I’m not actually aware of this being used but I figured someone tried it somewhere…)