long icicles hanging down from a roof in winter season

Is the harsh Ottawa winter causing you to have icicles hanging off the eaves of your roof? Are you concerned they may fall off, causing damage and possible injuries? In this post, we’ll review information about why and how icicles form, alongside what you can do to mitigate this problem.

Difference Between Ice Dams and Icicles

Firstly, it’s important not to confuse ice damming and icicles. Ice damming on a roof is caused by a poorly ventilated and poorly insulated attic and happens after heavy snowfall in cold weather. When temperatures warm, a large pool of water forms behind a layer of ice, which is caused by the melted snow. When this happens, water is likely to leak through the ceiling. On the other hand, icicles are generally not a roofing problem. They simply occur when melted snow turns to water and leaves the edge of your roof. 

What Causes Icicles to Form on Your Roof? 

Regardless of how well an attic is insulated or ventilated or how well the roof is installed, icicles can form off the edge of any roof. Icicles generally form on mild sunny days when the warmth melts the snow, while temperatures drop below freezing at night, hardening the melted snow into ice. Due to this process, icicles tend to get longer and thicker over time.

If there are no eavestroughs or gutters on your roof, then there is no way to stop icicles from forming. However, if icicles form even when there is a trough, that means that the trough is frozen full and water is getting by the trough somehow, either over it or behind it.

Dangers of Having Icicles on Your Roof

Two men holding buckets indoors under leaking roof.


Icicles on a roof pose serious dangers to your home’s structural integrity and even the health and safety of you and your family. Here are some common risks you may face if you do not address the issue promptly:

Eavestrough Damage

When icicles and ice dams form at the edge of a roof, they fill eavestroughs with ice, which can cause them to bend, break, or even fall off completely. Damaged gutters, in turn, may lead to damage to your downspouts, fascia, and other elements of your roofing system. If not repaired immediately, the issue can cause additional moisture infiltration and water damage to your home down the road.

Roof Leaks

In a nutshell, icicles are still water, which means they keep your roof wet for weeks at a time. This can eventually lead to water penetrating through your roof decking. When this happens, you can expect damage to your roof shingles and flashings, as well as potential moisture and mould issues in your attic.

Structural Issues

As mentioned above, if water gets trapped between your roof surface and wooden roof decking, it can lead to mould and mildew growth. This excess moisture and humid conditions can cause the wood to rot over time, resulting in severe structural issues. Additionally, your roofing system may be compromised, which can put the health and safety of you and your family at risk.

Damp Insulation

In addition to moisture problems in the attic and around the roof decking, water can penetrate your home’s insulation, causing it to become moist and lose its insulating properties. Damp insulation, in turn, leads to additional heat loss, which results in more icicles and ice dams, which cause more roof leaks and moisture problems. The only way to prevent or break this vicious cycle is to address the icicle issues promptly with an experienced roofing company.

Safety Risk

Most importantly, icicles on the roof of your home always have the potential to fall. This means that if you or your loved ones happen to be outside at the time, they are risking being hit by a sharp, glass-like object. If you do spot icicles on the edge of your home’s roof, warn your family and guests, but be cautious about removing them without the proper tools.

How to Remove Icicles on Your Roof

Of course, attempting to attack icicles with a hammer or shovel may be tempting. However, avoid doing so, as this can be dangerous and damage your eavestroughs and roofing.

If icicles are less than one inch wide and a foot long, they can be safely removed with a telescoping roof rake. Put on protective eyewear and gloves, stand firmly on the ground, and extend your rake from a distance to gently push the base of the icicles to break them off. If it is safe to access your roof, get a ladder and drop ice-melting tablets into the gutters. This can help liquify the remaining ice chunks.

How to Prevent Icicles on Your Roof

If icicles are a serious and continued concern for your home, there’s a clear way to avoid getting them altogether: install good eavestroughs with leaf guards and a heating cable inside the structure and downpipe. This stops the troughs from freezing or clogging up with debris. Thanks to these enhancements, water will flow off the roof and be caught in a trough and carried away down the downpipes, meaning no icicles can form.

However, replacing your gutters in the middle of winter isn’t feasible, meaning you might have to wait until spring and deal with icicles in the meantime. To reduce the likelihood of them forming, try following these simple steps:

  1. Clean snow off your roof in a timely manner after snow storms.
  2. Where possible, install a waterproof underlayment between your roof decking and flashings to prevent water damage.
  3. Add extra insulation to ceilings on the highest floor of your home to prevent warm air from escaping.
  4. Ensure that your attic has adequate ventilation to keep your roof deck cool and prevent snow from melting.

How Roofmaster Can Help

If you’re concerned about icicles along your roof and want to avoid DIY solutions, here’s how our team at Roofmaster can help:

Ice Removal Services

When you’re concerned about an accumulation of icicles hanging around your property, give us a call. Our team offers specialized services for removing icicles. Though they may seem harmless, when ice forms around the roof, it creates dams that block proper drainage. During freeze and thaw cycles, excess moisture can easily accumulate since there won’t be anywhere for it to drain out. This can make your roof vulnerable to rot and structural damage caused by all of that moisture. 

To prevent water from damaging the roof, it’s a good idea to have an inspection performed to check the condition of both the roof and ice buildup. We recommend having this done at least once during the season. For homeowners who keep having consistent icicles form on a frequent basis, then it might be best to have a roofing expert inspect a few times during each winter to remove any blockages before the spring melt-off arrives. 

Snow Removal Services

Snow accumulation is another common issue that contributes to ice dams and blockages. Heavy snowfalls can place a lot of pressure on the roof structure, and as that snow begins to melt during milder temperatures, it drains down and refreezes. This adds to the icicle problem. If there’s a significant build-up of snow along your roof and property, we can assist with that, too. During our roof inspection, we will remove snow and ice from around the eavestrough to avoid any negative impacts on the structural integrity of the roof and gutter system.

Roof Inspections

The winter season in Ottawa can be extremely harsh, which places a great deal of wear and tear on our exterior surfaces. That’s why it is imperative to have a general roof inspection done at least once per year to assess its condition. This is ideally done in early spring after the intense winter so any damage can be repaired before it escalates into a major and costly problem. During our inspections, we’ll take a thorough look at all of the components, including the flashing, shingles, chimney, and gutters, and keep you fully informed about issues of concern.

If you’re concerned about the condition of your roof this winter, don’t ignore it. Give us a call at Roofmaster, and we’ll send someone out to have a look, safely remove any ice build-up, and perform an inspection if needed.