What Causes Ice Dams On Your Roof and How to Safely Deal With Them

What Causes Ice Dams On Your Roof and How to Safely Deal With Them

Ice dams are a costly and dangerous condition for your home to experience. With the arrival of winter, and one expected to deliver large amounts of snow and ice in certain areas, preparing for ice dams is important for the integrity of your home’s roof.

In this article we will explore what causes ice dams, why they are dangerous and how to prevent and remove them safely.

What is an Ice Dam?

An ice dam is a collection of ice on your roof that frequently includes within the gutter system. Homes prone to ice dams are those that have excessive heat in their attic and experience fluctuating temperatures throughout the day and night.

You know you have an ice dam forming when you see ice inside your gutters as well as on the edges of your roof or along adjoining slope lines. 

What Causes Ice Dams?

Snow melt on your roof that ends up forming ice dams is caused when warm air from your home travels into your attic and warms up the underside of the roof. This warming, along with the weight of the snow, creates a melt layer at the bottom of the snow.

An ice dam is created when water from the melting snow runs down the roof and then refreezes before it has a chance to drip all the way down through your gutter system. 

The reason it refreezes is because the snowmelt dripping down the roof eventually travels over the eaves which do not have the same heat under them that the attic roof does. The cold air under the eaves returns the snowmelt to ice.

As the water refreezes, the ice buildup blocks any subsequent run-off, creating a "dam."

Where Do Ice Dams Occur Most Often?

There are certain areas of your roof that are more likely to form ice dams. They are:

  • Along your gutters

  • Along rooflines that join each other from different parts of your home

  • At the top of skylight windows

  • Against your chimney when snowmelt runs down the roof and gets trapped

  • Around roof vents

  • Along the roofline of dormer windows

Throughout the winter, when there is snowfall, be sure to keep an eye on these areas to spot ice dams that may be forming. If you see any ice dams, you may need to have it removed vs. waiting for warmer weather to completely melt the snow and ice.

The Damage Ice Dams Cause

Roof shingle damage caused by ice dams

Trapped water with nowhere to go may seep under the roof shingles where it refreezes, lifting the shingles from the roof. Lifted shingles are then at risk of collecting even more water, additional refreezing and further roof shingle damage. 

This damage creates potential leaks in your roof which become apparent when water seeps into the attic and then down into the home. Depending on the amount of water, this problem may be apparent quickly, or be something that develops and worsens over time until it is eventually detected.

Standing or seeping water will eventually rot out shingles, your roof, and the inside of your attic or home.

Gutter damage caused by ice dams

The added weight of ice buildup inside the gutters and on top of them can cause gutters to bend, crack or even break away from your roof. If this occurs, you are likely to experience seepage into your roof or walls as the ice eventually melts. 

Besides the potential for water damage, you will likely incur gutter repair costs as well.

Window and flashing damage caused by ice dams  

As ice dams form around window edges or flashing, any melting that occurs can get trapped and seep into cracks, causing internal leak damage to your home. The ice dams themselves may cause cracks in plaster, brick, or even siding, breaking it away from your home’s exterior walls. 

How to Prevent Ice Dams

Make sure you have proper insulation to prevent ice dams

The best way to prevent ice dams is to ensure that your home’s attic does not capture and trap excessive heat that will then warm the snow on your roof. 

Ice dams are an indicator of poor attic insulation, so check that first if you are experiencing ice dams. Replacing or adding an extra layer of attic insulation may ward off those pesky ice dams. 

Also consider your exterior wall insulation - especially those that are adjacent to your eaves. This is another troublespot. Blow-in insulation may be useful if your home is not properly insulated and is fairly easy to install.

Install gutter heating strips   

For areas of your home where you are especially concerned about potential ice dam buildup, such as over doors and windows, installing electric gutter heating tape can be a good temporary solution. Gutter heating tape is a strip, like a cable, that you place inside your gutter and then plug into an electrical outlet. An activated heating tape will help melt snow and ice so that it can run properly through your gutter system and away from your house.

Replace roofing underlayment

If you are in the process of replacing your roof shingles, make sure that you also choose a proper roof underlayment material that specifically protects against water seepage and ice dam damage. 

Membrane underlayment is especially effective in eaves, valleys, and dormer walls at preventing ice dam leakage into your home. Most newer homes that are built in cold climates have weather resistant underlayment installed but be sure to verify your underlayment if you are replacing or repairing your current roof.

Metal roofing panels

Standing seam metal roofs are great ice dam preventers but not everyone wants a metal roof or is in a position to replace their existing roof for a metal one. Instead, there are metal roofing panels that can be installed along the edge of the roofline to help prevent ice dam buildup. They usually require professional installation but especially handy DIYers may be able to complete the job themselves. 

Integrated ice melting systems

You can have an eave heating & melting panel system professionally installed which does a great job preventing ice dams along the eave of your home. They can be very pricey and will increase your home electrical costs. While effective for the eave, you may still experience ice dam buildup at the other common ice dam trouble spots mentioned earlier.

How to Remove Ice Dams That Have Formed

If you see ice dams forming, it is best to have them removed as quickly as possible before they increase in size and cause severe damage to your roof or home.

These are some DIY ice dam removing techniques that may work for you if your ice dams have not reached a critical size:

DIY ice dam removal techniques

Ice melt socks. Using nylon stockings, fill them with 2 - 3 pounds of calcium chloride ice melt and then tie off the ends. Place vertically along your roof slope and inside your gutters. They can be spaced several feet apart. The stockings will melt a channel in the ice allowing water to run off properly.

Use a snow rake. Using a purpose-designed “rake” to remove snow, these tools are especially useful before ice dams have formed. Using the snow rake, scrape the snow off your roof as high up as you can, removing as much snow as you can. They can be tricky to use unless you are able to stand on solid ground while in use, so while they are great for single-story homes, they might not be as helpful for some two-story homes.

De-icing cable. Similar in concept to the gutter heating tape, a de-icing cable can be installed on the roof, towards the edges, in a zig-zag pattern, and then plugged into an outlet to turn on. Again, these are most useful for one story homes as you will need easy access to your roof and will probably have to get on the roof for proper installation.

Professional ice dam removal

Removing ice dams is a bit of a project. If you are not up to the task yourself, consider hiring an ice damming professional. Professionals have the experience to navigate your home safely and remove ice dams without damaging your gutter system.

In order to safely eliminate ice dams without damaging your gutters or your roof, the gutters are removed first. Once they are removed, ice can also be removed from the impacted areas of your roof. Once the ice is then fully removed from your gutters, your gutters are reinstalled to their proper place.   

Looking for Ice Dam Removal on Long Island? 

Contact Ned Stevens of Long Island if you have ice dams on your roof or clogged gutters. 

We’ve been happily serving homeowners in Nassau County and Suffolk County since 1965 with gutter cleaning, ice dam removal, gutter repairs and installation as well as pressure washing and window cleaning services. 

Contact us today for a free estimate.

Erika Cruz

Erika began her career at Ned Stevens in September 2009 after 4 years of managing investment portfolios for banks and credit unions. She graduated with her business degree in Management in May of 2016 while working Full-time at Ned Stevens. With 11 years of gutter expertise, as office manager she is in charge of the day to day operation and is fully dedicated to her staff and customers.