Ice Dams – Everything You Need To Know To Protect Your Home

If you live in an area of the country where the majority of winter precipitation comes from snowfall, you may believe that concerns over roof leaks can be put on hold until the rains return in Spring. If this sounds like you, you’re not alone! However, the truth of the matter is, roof leaks occur during every season, and the misbelief that leaks only occur during the warmer seasons, has led many homeowners to neglect the signs of leaking, which leads to damage accumulating for months on end, and a large repair bill come spring. Knowledge is power, and in this case, potentially a huge cost saver, so let’s talk about the main factors that lead to roof leaks in the winter months, and how to prevent them!

The Leading Cause of Winter Roof Leaks – Ice Dams

What is an ice dam?

The leading cause of roof leaks in the winter months is by far ice dams. Ice dams are an accumulation of ice, typically at the eave of the roof, that form a ridge which can prevent melting snow and water from flowing off the roof.  

How do ice dams form?

Ice dams often form after particularly heavy snowfalls. Ice dams form when heat from the interior of the building rises into the attic and warms the surface temperature of the roof, melting the snow and causing it to flow down the surface. The melted snow then refreezes at the eaves, which are not exposed to heat from the attic.

Fluctuating winter temperatures can also result in ice dams.

What part of the roof are ice dams most likely to occur?

While ice dams most frequently appear on the eaves of the roof, this is not the only location where ice dams are found. Any part of the roof where snow can accumulate such as valleys, chimneys, skylights, and vents are subject to the formation of ice dams. Additionally, any parts of the roof that may be warmer than the rest of the roof, such as over bathrooms, or vaulted ceilings are common places to find ice dams.

The slope of your roof can also make your home more susceptible to ice dams. Flat roofs, which should never be truly flat, hold water longer than a sloped roof, which allows the melted snow to pool and eventually refreeze. But steep roofs aren’t safe from ice dams either! In contrast, due to the pitch of steep sloped roofs, snow can more easily slide down the roof, forming a buildup at the eaves and gutters which can lead to ice dams! 

Other factors such as the complexity of your roof, poor or unbalanced ventilation, and unbalanced insulation can also lead to the formation of ice dams.

Ice dams on the eaves of a home, causing an accumulation of snow and potential danger for those on ground level.

Do Ice Dams Cause Damage?

Damaged Decking, Attic, & Interior

Ice dams cause damage in a few different ways. The most common way that ice dams cause damage, is when the water that is unable to drain off the roof, seeps back under the shingles. Since shingles are designed to shed water and not hold water, shingles that are exposed to water for an extended period of time are prone to leaking. While the installation of proper underlayment can help prevent water reaching the wood deck, they are not designed for prolonged exposure to the elements, and will eventually degrade. Once water reaches the wood decking, it is only a matter of time before the wood begins to rot, and water finds its way through the deteriorated decking or the gaps in the sheathing, to the attic, where it can cause a host of expensive issues.   

Lifted Shingles & A Compromised Roofing System

Water that seeps under the shingles can also freeze. Along with their overlapping design, shingles use an adhesive strip, as well as nails to secure it to the roof and create a watertight seal. When water is allowed to seep under the shingles due to ice dams, ice that forms under the shingles can break the watertight seal, causing shingles to lift up and fail to reseal. Not only is this an issue when ice dams are present, it creates the possibility of leaks for all future exposure to precipitation.

Damaged Gutter System & Foundation

It’s important to be aware the upper portion of your home isn’t the only area subject to damage from ice dams. Your roof system is designed to work in tandem with your gutter system to drain water away from your home. When ice dams form on the eaves of your roof, there is a high probability that ice will also form inside or around your gutters. Gutters blocked with ice do not allow the water that enters the gutter system to drain, and rather than disposing of the excess water away from your home’s foundation as it should, the water spills over the edge of the gutters, running down the face of your home, and pooling around the foundation.

*Tip: Icicles are a sign that water is accumulating rather than draining.

The larger an ice dam becomes, the more weight and pressure it puts on the gutter system. As gutter systems are designed to hold a limited amount of water, not ice, the additional weight and pressure from expansion can bend or distort your gutters, and even cause your gutters and downspouts to detach from your home. A failed gutter system will allow water to pool around the foundation of your home, which can cause some very costly repairs depending on the extent of the damage.    

How To Prevent Ice Dams

The best way to prevent damage from ice dams is to prevent ice dams from forming in the first place. While no methods are a 100% guarantee against the formation of ice dams, there are steps you can take to minimize the chances of ice dams forming on your roof.

  1.  Insulate the attic floor – Proper insulation can help prevent heat from escaping through the roof and melting the snow on the roof.
  2. Ventilate the attic – Proper ventilation can help regulate the temperature in the attic and prevent heat from building up.
  3. Use a dehumidifier – If you are using the attic as a living space or for storage, the presence of moisture in the air can contribute to the formation of ice dams. Using a dehumidifier can help reduce the amount of moisture in the air and prevent ice dams from forming.
  4. Use heat cables – Heat cables, also known as roof de-icing cables, can be installed on the roof to prevent ice dams from forming. They work by using electricity to generate heat, which melts the snow and ice on the roof.
  5. Keep the gutters clean – Clogged gutters can cause water to back up on the roof, which can lead to ice dams. Be sure to keep your gutters clean and free of debris to help prevent this problem.
  6. *Install an ice & water barrier underlayment – Ice & water barrier is a specialized underlayment that serves as extra protection against water infiltration on areas of the roof that are prone to water accumulation, such as the eaves and around roof penetrations.

*While Ice & Water barrier won’t necessarily help prevent ice dams from forming, it can help prevent water damage from occurring should water penetrate beneath the shingles.

Ice dams on the eaves of a roofline leading to the formation of icicles.

How to Remove Ice Dams Once They Have Formed

If it’s too late to prevent ice dams and the weather won’t be heating up enough to melt the ice dams on its own, then the ice dams will need to be removed to prevent water damage from occurring. Please be aware that we never recommend homeowners getting on their roof, especially in conditions where ice dams have formed, as your roof will be very slippery. If ice dams have formed, we always recommend hiring a professional to prevent injuring yourself, others on ground level, or damaging your roof! If you do decide to tackle the issue of removing ice dams on your own, utilizing methods that can be applied from ground level are the safest bet. 

  1. Remove the existing snow – Since melting snow is the culprit for ice dams forming in the first place, removing the snow from your roof will prevent additional ice dams from forming. To remove snow from your roof, a roof rake, or a plastic shovel with a poly cutting edge can be used. Never use a shovel with a metal edge, as this can damage your roof.
  2. Steam – The use of a professional grade steamer operating at around 250-290 degrees Fahrenheit, is one of the most effective and safest methods for removing ice dams. However, since this method requires professional equipment, and must be performed from the rooftop, this truly is a job for professionals only.
  3. Hot water – If you have a hot water source that’s accessible with a hose, hot water can be used to melt ice dams. If you use a hose to remove ice dams, you need to make sure that the water is expelled at a low pressure. While options such as pressure washers with built in water heaters can remove ice dams more quickly, pressure washers damage your shingles by removing the granules from the shingles, and can even rip holes in the shingles at close distances. If you opt for a pressure washer, make sure to go with an option that allows for adjusting the pressure to a MUCH lower psi.
  4. Pantyhose/Socks filled with calcium chloride – Dealing with ice dams doesn’t necessarily mean removing all the ice from your roof, although that is the ideal solution. By creating channels in the ice dams at various points, you create an exit point for water to drain from the roof. Chemicals that melt ice can often damage your shingles, metal (such as nails and flashing), as well as the landscaping around your home.

    However, one method to prevent damage while melting channels in the ice dams, is to fill pantyhose or tube socks with calcium chloride, and place them vertically at various points along the ice dams.  To avoid the necessity of getting on your roof, you can tie strings around the ends of the pantyhose/socks. *Please note that calcium chloride is much safer for your roof and vegetation than rock salt/sodium chloride!


Other Causes of Winter Roof Leaks

While ice dams are the most common cause of winter roof leaks, they’re certainly not the only cause. While it’s more likely to snow than rain in the winter, rain does still occur, and all the same causes of roof leaks that occur in the warmer months, can still cause leaks in the winter.  

  • Poor roof ventilation – Insufficient roof ventilation can cause heat and moisture to build up in the attic, which can lead to condensation and ice dams.
  • Clogged gutters – Clogged gutters can cause water to back up on the roof, which can lead to leaks. Be sure to keep your gutters clean and free of debris to help prevent this problem.
  • Poorly sealed flashing – Flashing is the thin strip of metal or other material that is used to seal the edges of a roof. If the flashing is not properly sealed, it can allow water to seep through and cause leaks.
  • Damage from debris – Debris such as branches and leaves that accumulate on the roof can cause damage to the roofing material, leading to leaks. This can be especially common in the winter, when snow and ice accumulation cause branches to break free from the tree.
  • Old or worn roofing: As roofing material ages, it can become brittle and more prone to cracking, which can lead to leaks

Keeping Your Roof Leak Free With A Brahma Maintenance Program

Ice dams are common problems throughout the northern United States, but there are solutions to preventing ice dams and the damaging water entry they can cause. If you have property in Northern Colorado, consider checking out the Brahma Roofing & Construction maintenance program, which can help identify and address the root cause of ice dams on your property before they occur, as well as providing professional removal of ice dams if they are already present. Ice dams are a winter menace, but by utilizing the information provided, you can help keep your home warm and dry throughout the winter season.

A home with an accumulation of snow and ice dams on the eaves, valleys, and over heated spaces.

Leave a Reply