Ice Dams
January 16, 2017

We are in that time of the year where we are seeing those beautiful icicles hang from your house. All though they look nice, they are a precursor to ice dams. Ice dams are not beautiful.

What are Ice Dams?

Ice dams occur when the snow on your roof melts from the peak and then re-freezes when it reaches your eave or gutter. This constant thaw and freezing will start to build an ice dam. The ice dam will prevent water from flowing off your roof and into your gutter. Instead it will build up until starts to penetrate your roof. The ice will break the seal of your shingles and go back into your home. If you have not replaced your roof with in the last 15 years, you may or may not have an ice & water barrier to protect you. Without this barrier, the water will find its way into your home and cause extensive damage along your walls. You will see water stains along the exterior walls. That’s just what you see. The largest damage will occur in your attic space. Deterioration of insulation, rotting structure members and severe water damage will build on itself over the next few years. When you finally address it, it may be too late.

How to Deal with Ice Dams

Ice dams can be mitigated throughout the winter, but it’s not easy. Easiest thing to do is keep snow off your roof. You can read about that in a previous post “Snow on the Roof.”


Another way mentioned in “Snow on the Roof” is using heating cables, but these need to be installed before the snow flies. Once ice is in the gutter or on the eaves it’s already too late. Never lay cables loose on top of ice.


An effective short term solution is to throw salt bombs on your roof. Take an old pair of pantyhose, fill with Potassium Chloride and throw on top of the ice dam. In a few days, no more ice dam. Potassium Chloride is not harmful to vegitation, doesn’t leave salt stains, and is readily available at most hardware stores. (Ace carries Diamond Crystal Potassium Chloride Pellets for $26 for a 40 pound bag).


The professional solution is to use a steamer to melt the ice off. Using a high pressure steamer will plow through the ice in short order and protect your roof from more damage. However, they are spendy units and requires you to get on the roof, while it is covered in ice and snow. Purchasing your own unit is probably not the most cost effective option for the average homeowner.


How NOT to Deal with Ice Dams

NEVER use a power washer. Although most power washers will produce heat and a narrowed water jet to clear your ice dam, they will also quickly remove your granules. Thus, causing more damage to your roof. Also, you are adding more water to the problem.


NEVER use a pick axe, axe, hatchet or any other ice chopping device. If you are not careful, you will puncture your roof and create a water penetration point. Again, causing more damage to your roof.


NEVER use a torch. Your asphalt roof and its surroundings are combustible. Surprisingly, some still see these as a good method. Some so-called ice dam removal experts use this as their primary response. Do not allow it!


NEVER use ordinary salt such as the stuff you use on walk ways. This will deteriorate your roof after prolonged use. Also, will damage your gutters and trim metals. As mentioned above, only use Potassium Chloride.


Long Term Solution to Ice Dams


The long-term solution to ice dams is correcting the ventilation issue. Yes, ice dams are not supposed to be a normal thing. The reason why snow melts from the top and re-freezes at the bottom is because of poor ventilation. The roof needs to be the same temperature as the outside. This cannot be achieved if you have poor air intake or poor air exhaust.


As the picture shows, cool air is supposed to enter your roof from the eave and flow through to the top. This allows the hot air to escape. If your roof line does not have intake, then hot air stays trapped. If your roof line does not have adequate exhaust the hot air is trapped.


You do not need to replace your roof to have your ventilation corrected, but if you are having your roof replaced, you should always have the roofing contractor verify that the ventilation is correct. There is a simple mathematical equation that every roofer should know to determine if the ventilation is correct. If you want to calculate on your own, here is a great resource:


What’s Next?

If you find yourself with a large ice dam, we can help with that. We will clear your ice dam for you using the best technology available to do it right, and preserve your roof from further damage. However, you should know that clearing ice dams will be a reoccurring issue until the greater issue of ventilation is addressed. We can also give you a quote on correcting your ventilation issue. Click the offer button below to set an appointment with YOUR TRUSTED ROOFING ADVISOR and we can give you an estimate to clear your ice dam and correct any ventilation issues.