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Understanding the Connection Between Icicles and Poor Insulation: Causes, Risks, and Solutions

During cold winter months, the sight of icicles on the roof doesn’t come as a surprise. In fact, many people will completely disregard this issue, blaming it solely on low temperatures. However, if you’re a homeowner, you may have heard of the connection between roof icicles and bad attic insulation. What do icicles on your house mean, and when do roof icicles become an indicator of poor insulation? Read on to learn more.

Do Icicles Cause Roof Damage?

When it comes to determining whether icicles are a threat to your roof or not, the number of icicles plays a vital role. A couple of small icicles on your roof are usually nothing to worry about, as they’re a natural consequence of water reacting with cold air and turning into ice.

However, a significant number of icicles on the edge of your home’s roof could mean that your existing insulation is insufficient and that you may have to reinforce the insulating barrier to prevent ice damming.

How Do Icicles Form?

Icicles on the house will occur once water dripping off the edge of the roof freezes when the temperature drops below freezing.

Are icicles bad for your roof and do icicles mean poor insulation? Not necessarily, as icicles can also appear even with proper insulation and proper ventilation.

In case you’ve installed good eavestroughs on your roof, the number of icicles should not be overwhelming. However, the absence of proper eavestroughs, clogged or frozen eaves, as well as a lack of good attic insulation could lead to the formation of a greater number of icicles, and eventually - ice dams.

Do Icicles Always Mean I Have an Ice Dam?

No, icicles don't always mean there are ice dams on your roof.

However, to be able to determine whether ice imposes a threat to your house, it is important to understand the difference between an icicle and an ice dam.

Icicles Vs. Ice Dams


Icicles can form without ice dams. This happens when snow melts on your roof, and the water refreezes as it drips off the edge. As we’ve mentioned, an icicle is a cone-shaped ice formation hanging off the edge of your roof, and it is not necessarily indicative of improper insulation.

Generally, an ice dam may not be present if the icicles are only on your gutter. While some icicles on the roof are usually not considered harmful to your home, the same can’t be said for ice dams.

Ice Dams

An ice dam is essentially a buildup of ice on your roof (usually in the gutter) that forms during heavy snowfall in extremely low temperatures. Ice damming on your roof can be a symptom of poor attic insulation, and it can even lead to further damage, such as water leaks.

What are the signs of an ice dam? Here are a few:

  • Ice Buildup Along the Eaves. You probably have an ice dam if you see a thick ridge of ice at the edge of your roof.
  • Thick Icicles On the Eaves and Soffit. Another sign of an ice dam is a large cluster of thick icicles on the eaves or soffit.
  • Water Stains. Finally, take a quick peek in your attic and look for water stains on the ceiling or walls. If you see water stains, ice dams are probably an issue.

What To Do About Icicles On Roof?

A couple of icicles forming under the eaves shouldn’t be too much of a problem. That being said, a greater accumulation of icicles around the roof imposes a threat to your safety, and it could also lead to ice damming, which is a serious issue.

If icicles tend to form on your roof, one of the solutions could be to install proper troughs and ensure that they’re clog-free. Adding a heating cable inside these troughs could also prevent freezing in winter months.

Keep in mind that preventing icicle forming on the roof if you don’t have troughs or gutters is quite challenging, as having a functioning drainage system is extremely important.

Persistent and substantial icicle forming and ice damming could be a warning that your attic requires additional insulation. In this case, you may want to reach out to an experienced insulating contractor and schedule a consultation to find the best insulation solution and avoid potential water damage, as well as increased energy costs.

Why Should You Keep Your Home Insulated?

When snow accumulates on your roof, if your attic is not properly insulated, the striking temperature difference could lead to ice damming. As the heat inside your poorly insulated attic will melt the snow, the melted water will end up in the gutter where the refreezing will occur due to a contrast in temperatures.

This is exactly how ice dams are formed inside the gutter, jeopardizing the draining process and potentially leading to mold, as well as structural damage to your roof.

Quality air sealing should keep your attic cool enough to prevent the snow blocks from melting and overwhelming the gutters.


Accumulation of ice on your roof, whether it be icicles or ice dams, could be a warning that your attic is not properly insulated. Do you need your attic insulation improved? We can help. Schedule a free consultation with an iFOAM insulation specialist at (855) 935-4723 today to learn how you can protect your home from ice damming, water leaks, and structural damage.