8 Tips To Prevent Ice Damming On A Roof

Avoiding Roof Ice Dams

Those icicles dangling from the eaves of your house may look picturesque in a wintery way if you live in Ontario, but they're a sign that your roof could be suffering damage from ice damming. Your roof is like a shield for the rest of your house, so it's built to last and can take a lot of abuse, but its longevity depends on its ability to rid itself of excess water, and that ability is seriously hindered when ice dams form.

So, what are the best ways to prevent ice damming on a roof? Why does it matter so much? And what exactly is ice damming anyway? Here are some answers to those questions from the brokers at Morison Insurance, along with tips and tricks for both fast, temporary solutions and long-term solutions when you need to know how to prevent ice damming on a roof.

What Is Ice Damming?

You may have a basic idea of ice damming, but because it happens way up there on your roof, it's challenging to get up close and see what's happening. Ice damming occurs when your warm roof begins to melt snow and ice, but the eaves—the part hanging over the edge of your exterior walls—are not warm. This means the excess snow that has fallen on your roof melts, and the water rolls down to the roof's edge, where it freezes and forms a "dam" of ice that prevents trapped water from falling off the eaves into your rain gutters. Instead, the water backs up on the roof and sits there, slowly seeping into your roof shingles, where it causes much more significant problems like wood rot, damaged attic insulation and mould growth.

Damage to your house is undesirable, but it's not the only reason to prevent ice damming on a roof. By stopping the formation of ice dams, you can avoid the damage that makes your house less energy efficient and costs you a lot of money on your energy bills. You can also prevent the need to file an insurance claim on your homeowner's insurance, which means you can keep your premiums low and avoid losing claims-free status.

What Does Ice Damming Have to Do With Your Attic?

The key to knowing how to prevent ice damming on a cold roof is understanding why it is warm—and it has a lot to do with your attic. Your house either has a warm attic, where the attic space is a habitable area of the house that is insulated, heated, and has one or more rooms, or a cold attic, where the attic space is not habitable. A cold attic is more of a crawl space between your roof rafters and the top storey of your home, with insulation on the attic floor to prevent heat from escaping. (It's typically not a natural floor but rather the upper side of the ceiling for the rooms below.)

We all know heat rises, and whether you have a warm or a cold attic, it's essential to have adequate insulation in place to prevent heat from rising through the roof slopes and causing problems such as ice damming. In a cold attic set-up, which is the more common variety, it's also essential that the roof be adequately ventilated so it can vent out excess heat and humidity to prevent heat and moisture from building up in the attic space and causing not only ice damming but also other severe issues like flattened, rotting insulation, mould growth and rotting rafters or support pillars.

Temporary Solutions to Prevent Ice Damming On Roof

The best-case scenario is to prevent ice damming on a roof surface before it can occur with permanent solutions already in place before the snow starts flying. But realistically, that only sometimes happens. Sometimes, you find yourself in a situation where an ice dam has already formed or is threatening to form, and you must deal with it quickly.

1. Remove Snow With a Roof Rake

It should be removed if there’s a layer of snow piling up on your roof, mainly if it's sticking to your eaves. Even if it's not gathering on the eaves specifically, the weight of a massive dump of heavy snow can be a significant strain on your snow-covered roof, and it makes sense to remove it before it causes damage.

Please note that when we suggest you remove the snow buildup with a rake, we're talking about a snow rake or lightweight roof rake designed for this purpose, not the kind of rake you use on your lawn. You want to avoid scraping or chipping away at the ice on your roof with anything pointy or sharp because it's all too easy to damage the roof shingles underneath accidentally. Different varieties of long-handled roof rakes are available, most of which can be used from the ground. Just be cautious and clear of the eaves so you're not hit with falling ice or excess snow.

2. Targeted De-Icer Application

If you've got a nasty ice dam forming on the edge of your roof, you've got to do something to get it off, and a rake may need to be heavier-duty to get the job done. It makes sense to use a de-icer to remove ice. Still, it's not a good idea to sprinkle it around on the entire roof because there's no way to get it off, and the chemicals can eat into your roof shingles over time, causing even worse damage than the ice you're trying to get rid of.

Don't worry, there's a simple solution using an inexpensive item you may already have in the house—a pair of pantyhose. Select a pair you no longer want since they won't survive this experiment, and fill a leg with calcium chloride de-icer. Tie it off and drape your "sack" of de-icer over the ice dam. You don't want it to parallel the roof edge but to cross it and hang off a bit. Leave it there for a couple of hours, and it will melt the ice underneath it, creating a channel through which the water can flow to get to your gutters. Keep an eye on it and don't leave it there longer than necessary, as the calcium chloride can corrode your gutters, flashing and other roof parts. You may need to repeat the process a few times in different places, but at least it will keep the water moving off your roof and prevent severe ice dam damage.

3. Cool the Underside of the Roof

Suppose you already have an advanced ice dam situation, and water is dripping into your attic. In that case, you must stop the dripping before you can handle the overall problem more proactively. The fastest, easiest way to accomplish that in an emergency is to carry a box fan into your attic space and aim it straight at the area where the roof leak is coming from. The concentrated blast of cold air will cause the dripping water to freeze and temporarily halt the leak until you can deal with it more permanently.

Permanent Solutions to Prevent Ice Damming On Roof

Once you've had the unpleasant experience of scrambling to prevent ice damming when it's already happening or about to happen, you'll probably be interested in finding out how to prevent ice damming on a roof more permanently so you can have peace of mind that comes with knowing your roof—and by extension, the rest of your house—are safe from severe water damage.

Most methods of doing this aim to keep your roof and your eaves at the same temperature so you don't have snow melting on the warm part and then forming ice dams on the cold eaves. The best solution for your home will depend on what caused the issue in the first place, but here are a few ideas on how to prevent ice damming on your roof proactively with permanent ice dam solutions.

4. Top-Up Attic Insulation

Did you know that most homes lose about a third of the heat their HVAC systems produce through the attic and roof? This makes plenty of sense if you think about it, since heat transfers through ceilings and will continue rising unless it's stopped by something. That "something" should be your attic insulation, but over time, your insulation can flatten, deteriorate, or get moved around and leave exposed patches that are a magnet for heat loss. It pays to top up your attic insulation every once in a while to prevent ice damming on your roof or have an insulation professional tackle the job every few years to ensure your house stays snug and cozy and your attic stays cold.

5. Seal Gaps Between House and Attic

The reasons why it's so important to ensure your attic has adequate insulation are also why you need to seal gaps that let thermal energy escape into your attic space. That could mean anything from under-insulated walls and gaps around plumbing pipes to holes in drywall or cracks around lighting fixtures. Getting them sealed up can be a big job, as it involves climbing into the attic space, clearing away insulation, sealing up gaps with caulk or foam insulation, and then putting all the insulation back in place. If you're not up to the task, enlist the help of professionals who know exactly what to look for when taking steps to prevent ice damming on a roof and can deal with air leaks even in difficult-to-reach areas.

6. Add or Replace Ridge Vents and Soffits

You likely already have ridge vents on your roof and soffit boards under your roof eaves, but adding these roof ventilation features is an excellent idea if you don't. They'll keep heat and humidity moving out of your attic space so you can avoid heat loss and prevent ice damming on the roof. If you already have attic ventilation, but it has been a while since it has been maintained, replacement or repair may be necessary.

7. Install Heating Cables

This particular solution needs to be installed before winter, but it's an effective method of ensuring your roof and eaves are all more or less the same temperature. Heated cables don't address underlying issues that cause heat loss, but they are an effective way to prevent ice damming on a roof. Electric heat cables, which are also called de-icing cables, are an ice dam prevention product that is basically what it sounds like cables installed on your roof and eaves that heat up and melt snow, keeping water moving into your gutter rather than letting ice build up on the eaves. These electric heat cables are installed across the roof in a zig-zag pattern and can be switched on when snow falls.

8. Maintain Gutters

This last point isn't exactly about how to prevent ice damming on a roof, but it's a really important step to prevent the same types of damage that occur with ice damming. If the water makes it past your eaves, but you have broken or clogged gutters, the water will just back right up onto the eaves again and lead to ice dam formation, among other problems, because there's nowhere else to go. Gutter damage can cause enormous issues for your roof and many other parts of your house, including cracked foundations, due to the water not being disposed of correctly by your gutter system. It's worth considering adding gutter guards that let water in but keep out other debris, such as dead leaves and pine needles that cause clogs, and keeping your gutters clean and well-maintained.