Funny how some things that are beautiful can also be damaging. For example, ice storms that coat tree limbs or more commonly, icicles which are born of a condition known as an ice dam. Ice dams are a 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 in some cases, even contribute to mold.
Roof ice dams will form when snow is melted by a warm roof, creating water running 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. As the bottom of the snow pack continues to melt by the warm roof surface, water continues to flow down the roof surface until it hits the cold ice, refreezes and winds up increasing the size of the ice dam.
Heavy Snow Makes an Ice Dam Worse
Why? Because snow is a great insulator. Snow that is in contact with your roof will melt because the attic is above 32 degrees Fahrenheit to the point that it warms the outside roof surface and melts the snow. The snow acts as an insulating blanket allowing the outside roof surface to warm up easier from the warm attic space, thereby melting the snow faster.
Tips for Battling Ice Dams
Although ice dams are best defeated in warm weather with proper roof ventilation, there are some things you can do to beat back the formation and prevent the damage of ice dams in winter.
Use a Roof Rake: From the ground you can use a special tool called a roof rake. A roof rake is a long handled inverted shovel you use to pull snow off the roof toward you. The tool can be fixed length or telescopic and should be used to remove about 3-4 feet of snow from the roof edge. This does not solve the problem but just reduces the snow insulation layer at the roof edge which will slow down the formation of the ice dam.
Use Calcium Chloride: If you want to try and bring the battle to the ice dam it will require getting on a ladder to apply calcium chloride or some similar ice melt product directly on the edge of the roof. Make sure to use the ladder safely. If you don’t want to use a ladder and fancy yourself good at tossing things, you may want to try a product called Roofmelt which is round calcium chloride tablets you toss up on the roof.
Steam Removal of Ice Dams: OK, now you are calling in the big guns and opening up your check book. Of course you are also getting the job done while safely on the ground looking out from your window while drinking a hot cup of coffee, so hey, it’s all a trade off, right?
Steam removal is the most effective and safest way to completely remove your ice dam problem. I want to clarify, I am not recommending hot high pressure power washing which can damage your roof, but rather low pressure steam which is safe and effective. The downside is there are less roofing contractors that have this specialty steam equipment than have a power washer. But finding the right contractor will be worth the effort, even if you have to pay a bit more for the service. You can tell a steamer as it will have no trigger on the gun handle and the hose will be black. Just make sure you don’t get a contractor with a high pressure power washer up on your roof.