Everything You Need to Know About Ice Dam Prevention

Editor’s Note: This blog was originally published in November 2015 but has been updated to include additional tips on ice dam prevention.

If you’re starting to feel a winter chill in the air, then now is the perfect time to make sure that your home —and everything in it—is safe from the most common hazards of the season. From freezing rain and ice to heavy sleet and snow and drastically fluctuating temperatures, your house can take a serious beating during this time of year.

But of all the perils of winter, perhaps the most harmful threat to your home is the infamous ice dam. Every year in New England, ice dams cost homeowners millions of dollars and cause serious property damage, including:

As your local insurance agent, the team at HIG wants to do everything we can to make sure you are fully informed on how to prevent an ice dam from taking hold of your home. There are many things you can do to minimize the likelihood this destructive winter hazard will affect your home, and we are here to give you some tips and straight talk about all of them.

How does an ice dam form?

An ice dam typically starts off as beautiful little icicles along the edge of your roof. However, the presence of these icicles generally means you have snow on your roof that is melting and refreezing as it flows over the edge of your roof rather than running off your roof and down your gutters as normal. This continuous melting and refreezing process is exactly what can cause innocent-looking icicles to turn into a monstrous ice dam.

You may not initially notice a problem developing when icicles are smaller. However, if you don’t get rid of this ice and safely clear your roof of melting snow right away, you can end up with much larger, thicker ice spears along your overhangs and an even bigger barrier to water runoff. Once these massive icicles form, there is a very high likelihood that some of the backed-up water from the snow melt could get under your shingles and down into your soffits, which are the underside of the overhang on your roof.

If you do not make any moves to eliminate the mounting ice and snow from your roof, then the final stage of ice dam growth may set in—which is when the ice dam creeps its way down the side of your house. When this happens, there is almost no doubt that a massive amount of water is finding its way into your home, not just through your roof, shingles, and soffits but possibly through your wall cavity, as well.

It probably goes without saying, but water in your home can cause extensive, and sometimes irreparable, damage to anything that stands in its way, from structural elements like ceilings, walls, and gutters to personal belongings like furniture, electronics, and wall hangings.

Fortunately, there are several things you can do before winter fully arrives that should help deter an ice dam from forming on your home.

Three things you can do to help prevent an ice dam

In order to form, an ice dam needs three conditions: snow, heat to melt the snow, and cold to refreeze the melted snow into solid ice. Coincidentally, there are also three important steps you can take to try to mitigate these factors and potentially avoid an ice dam emergency this winter.

1. Clear your roof of snow and ice. It doesn’t take much snow to lay the foundation for an ice dam. In fact, just one to two inches of accumulation on your roof is all an ice dam needs to get started. That’s why it’s smart for homeowners to purchase a special tool, called a roof rake, that can be used to safely remove excess snow from a roof and break off little icicles from overhangs.
   Now for some straight talk from HIG about ice dam prevention: The genius of the roof rake design is that it enables you to stay firmly on the ground while getting snow and ice off your home. It is way too risky to get on your roof to remove snow or to use a roof rake while standing on a ladder. It’s also important to note that these tools are intended for use with single-story homes only, so you should consult a professional for snow removal on larger homes, as well as when there has been a particularly heavy snowfall.
2. Properly insulate your home to stop snow melt. The main culprit of snow melt is typically the upper part of your roof. This area of your roof is directly over your home’s living space and absorbs heat that escapes from your house. To prevent heat from warming this area of your roof and to thereby slow the snow and ice melt, you should focus on proper insulation. Attic floors and ceiling insulation should be continuous and consistently deep, and address problem areas such as above exterior walls. In addition, you should pay special attention to airflow through even the smallest holes, such as gaps in drywall and spaces around lighting fixtures, wiring and plumbing penetrations, and bathroom exhaust fans.
   Now for some straight talk from HIG about ice dam prevention: Unless you are a trained insulation installation professional, insulating your home is not a DIY project. While it might save you some money initially, if not done properly, you could be left with a drafty home, mold and rust issues, and, even worse, severe health problems. Plus, if your home is poorly insulated, you may end up with that ice dam you were specifically trying to avoid!
3. Use an effective ventilation strategy to cool your roof. If you can keep your entire roof as cold as the outdoor air, you have a good shot at warding off an ice dam. The best way to do this is to install a soffit-to-ridge ventilation system to run continuously along the length of your home. These types of vents work together to cool your roof’s sheathing by flushing out warmer attic air and sucking in replacement cold air.
   Now for some straight talk from HIG about ice dam prevention: Insulation, dust, and dirt can easily build up in your roof and soffit vents and block the critical air flow they are promoting. For this reason, it’s important that homeowners clean out these vents once or twice a year. While some people venture to do this cleaning on their own, the risks might far outweigh the costs and benefits of hiring a professional to do this task for you.

By making sure your home is well ventilated, insulated, and clear of snow and ice all winter, you are attacking the three root causes of ice dams and doing everything you can as a homeowner to try to prevent this issue from affecting your property.

HIG is here to help you with ice dams and other winter disasters

So, you thought you had blocked all the airflow leaks in your home; you were certain that no heat was escaping your home and warming the roof; and you have been doing your best to keep up with the snow and ice accumulating on your roof. And yet, despite all your best efforts, you are seeing signs that you may have an ice dam. What do you do?

If the ice dam is in its early stages, you may be able to get rid of it yourself with calcium chloride, a chemical melting agent that most local hardware stores should carry. However, do not attempt to use other melting agents, such as rock salt. These compounds are highly corrosive and can cause serious damage to your roofing, siding, gutters, and downspouts, as well as poison any plants near the foundation of your house.

If you have an ice dam that has graduated into its later stages of development, we strongly recommend that you do not try to chip away at it. Especially if you are seeing water, structural, or other ice dam–related damage inside or outside of your home, it is wise to call a professional.

Also, since damage to your home caused by an ice dam is typically a covered peril in your standard homeowners insurance, you should call your local insurance professional if you experience an ice dam emergency. The team at HIG helps clients navigate the claims process by making sure homeowners remember to document all ice dam–related issues and repairs with photos, videos, and receipts.

As your local insurance agent, we are here to help you understand the hazards that can impact your home, not just in the winter but all year round. We also want you to know how your home insurance coverage is built to provide protection in many of these situations.

Please contact HIG today, and put our knowledge and experience to work for you.