Ice Dams: What Are They & How to Prevent Them

February 11, 2021

Last night in Philadelphia, a nice layer of fresh snow appeared and made for a very beautiful landscape! But with snow comes lots of extra worries for homeowners. Every homeowner already has to worry about shoveling snow and cleaning sidewalks, but did you know you also need to be worried about Ice Dams? But don’t panic! We have some tips and advice to help you avoid Ice Dams for the future and prevent them from causing any extra damage to your home!

What is an Ice Dam? 

An ice dam is made up of layers of ice that accumulate on the edges of your roof & is created when heat rises from a home, melting existing snow on the roof.  As the snow heats up the under the layer of the snow, it melts and causes water to run under the still-frozen snow down to the roof edge. At the edge, the water refreezes under the snow and forms a thin layer of ice.  As the process repeats, it forms layers of ice that increase in size as does the pool of water underneath it. This process can then force water under the roof covering and create pools of water. This then leaks through your roofing material and damage the interior of your home.  It can damage walls and ceilings and possibly trap moisture, which in a worst-case scenario can lead to mold and mildew build-up.

How to Prevent an Ice Dam:  

  1. First thing first – if you can safely access or reach your roof, remove snow from the roof. This eliminates the largest cause of Ice Dams – the build-up of snow and water!
  2. This is something that should be done year-round, but always clean leaves, sticks, and other debris from your home’s gutters and downspouts. This will allow a clear path for melting snow and prevent the water from pooling and getting trapped on your roof.  
  3. When was the last time you inspected your insulation? Do a check-up of the insulation and ventilation in your attic. Our experts recommend at least R-30 insulation value for an attic (R-38 preferred in northern climates).
  4. While you are inspecting your installations, check your attic for any insulate or seal penetrations such as vents. Make sure they are properly cleaned up and sealed up! 
  5. If you have any heat sources installed in open attic areas or directly under the roof, remove or relocate them! 
  6. Insulate light fixtures in the ceiling below an unheated attic space so their heat doesn’t reach the roof. 
For extra information, check out https://extension.umn.edu/protecting-home-rain-and-ice/dealing-and-preventing-ice-dams#take-immediate-and-long-term-action-1977660.