Icicles + Ice Dams on Gutters: Causes, Prevention, Removal

By Tom •  Updated: 02/27/21 •  10 min read

Yup. That’s an icicle that’s about 7 feet long hanging off the corner of my house.

Generally we have pretty manageable icicles, but this year our house — along with most of the neighborhood — has been plagued by gnarly icicles and dreaded ice dams due to a lot of snow and below freezing weather.

(Some of the below links are affiliate links which means I get paid a bit if you click through and buy something — it doesn’t add anything to your cost! Just helps keep the lights on.)

Below I’ve set out to give you the full lowdown on icicles and ice dams on gutters – why you get them, what to look out for, how to avoid them and what to do if you do get them.

Why do I have icicles on my gutters?

Icicles and ice dams are caused when you have a lot of snow on your roof that for one reason or another melts and then re-freezes when it rolls down to the edge of your roof and metal gutters.

This can happen when you have a few inches of snow on your roof and it is above about 20 degrees and either the sun warms your roof enough to melt some of the snow or your attic is too hot (above freezing) relative to the outside temperature. What’s happening is that the snow insulates the roof and while the outside temperature is below freezing, the snow that is touching your roof is below freezing.

The edge of your roof and metal gutter hangs off of your house and are colder than the rest of your roof that’s been heated by your warmer roof – particularly metal gutters.

The process of an ice dam forming

Your gutter downspouts may also be frozen and therefore blocked which causes a backup of water and ice. The water has nowhere to go so it flows over the edge of the gutter and freezes on the way down to form those lovely — though sometimes dangerous and damaging — icicles.

So adding more downspouts won’t help the icicle or ice dam situation.

So, what causes the warm roof? Heat leaking up to the roof in your attic. If you have leaks from your home going up into the attic, inadequate insulation between that heat and your roof and too much of a differential between the outside temp and your roof — you’re going to get melting and icicles.

If it gets really bad it can cause leaks which can lead to mold, rotting wood and even damage to drywall which can break apart and start wrecking your walls and ceilings.

Related: How to actually keep your underground downspouts from freezing

Are icicles on gutters bad?

Icicles on gutters are not always bad — it’s the type and size of icicles (and any ice dam above them) that determines if they are bad or not.

Small icicles are almost never a problem — UNLESS they are coming from behind the gutter instead of the outside edge. If it’s behind that could be causing damage to your fascia (which is the board on your house where your roof meets your wall) or it could be a sign that water is flowing into your house.

What’s EXTRA bad when you see icicles between the gutter and the fascia is if the icicles are a brownish color. This just about guarantees bad news because it’s a sign the water is passing through your wood first.

It’s ALSO bad if icicles are coming out of your soffit vents or are running down the walls of your house.

Okay, so that takes care of the small icicles.

Now how bad you’ve got it depends on the size and thickness of your icicles or ice dams. Once icicles get larger than 2 or 3 inches in diameter, you start to get into danger territory due to their weight and potential to cause damage or injury if they fall.

Ice dams are basically slabs of ice in you gutters and running up your roof a bit that blocks the flow of water off the roof. They really become a problem when they fully block any further water from running down, which then backs up the roof.

Your roof is meant to protect your home from water running DOWN the roof, not UP it. So with backed up water moving up your roof, you are at risk of getting a leak.

How to Stop Icicles and Ice Dams from Forming on Gutters

The most effective ways to prevent the ice dams and icicles on your gutters are to insulate your attic, pull snow down when it forms on the edge of your roof, add a heating element to your gutter and the edge of your roof and increase ventilation in your attic.

Do steel roofs prevent ice dams? No, they don’t outright prevent ice dams. The benefit you get from steel rooves is that snow is likely to slide down off of it easier, but just like any other roof if your roof is warm enough to melt snow and the edge of your roof is cold enough to freeze it, you’ll be in the same boat as everyone else who gets ice dams.

So let’s get into some more detail on the most effective preventive measures:

Keep your attic cool

If you’ve been paying attention you know the greatest contributor to ice forming on your roof is a roof covered in snow that is above freezing causing the snow to melt and roll down the roof and refreeze.

So how do you keep your roof the same temp as the outdoors?

  1. Don’t let heat leak up from your house into your attic. Seal any holes or gaps such as around chimney flashing and HVAC ducts. Seal up any gaps. Caulk any holes created by cables or other pipes coming into the attic. Basically check everywhere where air could be leaking through and stop it up.
  2. Add insulation to the floor. Again same concept to keep the heat out of the attic and away from the roof. You want an R-Value of 49 between home and attic. (R-value refers to insulation material resistance to heat flow — it’s the “R”esistance and the higher the number the more it will be effective at insulating.) I’d personally recommend getting a professional to help with any insulation – you can expect to pay around $2 to $4 per square foot.
  3. Ensure you have adequate ventilation. If you have existing ventilation check to see if it’s clear of dust and debris. Soffit vents and roof or ridge vents can help with cool air circulation. You want the air to move through so it keeps it cool. If you don’t have existing ventilation look into ventilating the eaves and the ridge of the roof. And to be clear this is ventilation in the roof, not between your attic and the rest of the house.

Pull Snow Down from Your Roof with a Roof Rake

Since the snow build-up is what provides the source of the water that eventually builds into icicles or ice dams, it makes sense that getting rid of some of that snow before it has a chance to melt will decrease or eliminate the ice build-up.

So get yourself a roof rake (Amazon) and keep that roof clear of snow.

Add a Heating Element to Your Gutters

The strategy here is to keep the ice melted once it reaches the edge of your roof and your gutters so that the water is able to smoothly flow all the way down and out before it has a chance to freeze.

Now adding a heating element can be a bit of a hassle. You need to:

  1. Buy the heating cables or heating elements. You can find a bunch on Amazon here.
  2. Set up or somehow run power out to the heating element.
  3. Install it
  4. Ensure it powers on and off when you need it to.

I haven’t done this myself so I can’t speak to how difficult it will be, so you might need a pro to help with this.

The most important place to put the heating element is IN your gutter and it MUST run all the way down the downspout in order to ensure the water is able to flow to the ground. If you don’t run it down the downspouts, you’ll just end up with frozen downspouts and backed-up water anyway.

It’s less important, but depending on your house may still be necessary, to also install a heating element along the edge of your roof, going up a foot or so and hanging off the edge by an inch or two. After all, the edge of your roof could be cold enough to cause an ice dam even if your gutters are running smoothly.

Get Heated Gutter Guards

If you install gutter guards you can get guards that come with a heating option.

Gutter Helmet has their Helmet Heat ice reduction system, for example. Edge Melt Systems is another example of a heated gutter guard.

How do you Get Rid of Icicles and Ice Dams on Gutters?

Okay, so it’s too late.

You already have these blasted frozen menaces hanging off your gutter and blocking up your roof, what can you do?

  1. Fill a stocking or sock with salt or ice melt and throw it onto your roof. A bit weird, I know, but it can work. It’s not guaranteed to work, but worth a shot if you have no other options. Fill a stocking or sock with salt or ice melt, tie it closed and tie that end to a long string so you can pull it down when it’s done its work. Throw it up there! It’s important that the stocking land perpendicular to the gutter and is positioned so that when it melts the ice a channel is created to release the built up water behind the ice dam.
  2. Should you break icicles off of gutters? If you just have icicles, you can safely reach them and they are not too huge, you can try to break them off using a hammer or really any hard object. Again, not really recommended but if the icicles are not huge or embedded in a giant ice dam but do present danger to people and things below, it might be best to try to knock them down.
  3. Use hot water to melt the ice. If you have access to a hot water source that you can hook up to a hose AND you can reach the icicles/ice dam you can spray down the ice dam and icicles until they melt enough away to allow the water to run down freely.
  4. The most fool proof option — and also the most expensive — is to call in a professional to steam off the ice.

Do Gutter Guards Cause Ice Damming?

Gutter guards are designed to keep debris and sticks and leaves out of your gutters to keep water flowing freely. BUT, they freeze over just like the rest of the gutter.

While they don’t cause ice damming but they also won’t prevent ice buildup.

Thinner gutter guards are more liable to melt faster, so that’s one notch in favor of thinner gutter guards. Also, you can follow the recommendation above and add a heating element to the gutter guard which will help the situation.

Related: How to Stop Gutters + Downspouts from Freezing in Winter


A few years ago I bought my first house. It’s 100 years old. It’s clearly had a history of less-than-professional DIY handymen/women. And APPARENTLY you’re supposed to actually put work and money into it if you don’t want it to look terrible or water to rain down on you while you’re sleeping. About YouTube Facebook Twitter Pinterest Instagram