Understanding Ice Dams and How to Prevent Them This Winter

Michigan winter has arrived! While many homeowners enjoy the beautiful falling snow, winter brings its own set of challenges. One of the most damaging issues is the formation of ice dams on roofs. Understanding what ice dams are and how to prevent them can save you from expensive repairs and keep your home safe throughout the cold months.

What Are Ice Dams and How Do They Form?

Ice dams are ridges of ice that build up parallel to the eve of the roof. They form when heat escapes from the heated interior space, and cannot escape the attic space quickly enough. The resulting heat build up warms the underside of the roof deck, which in turn melts the snow from underneath. The snow on top acts as an insulating blanket to keep the freshly melted snow in liquid form. The water slowly trickles down the roof slope until it escapes the influence of the heated area, where it re-freezes. As water continues to flow down to the same area, the ice grows into a dam that prevents further water from draining. This creates ponded water behind the dam. Once water is ponded behind the ice dam, it will infiltrate under shingles and into the home.

These are a few things required to form ice dams:

1. Below freezing temperatures.

2. Standing snow on the roof as fuel.

3. An attic space that is above freezing.

These things can remedy ice damming:

1. Better insulation, including overall R value and blocking escape areas like lights and vents that directly dump heat into the attic.

2. Better ventilation to dilute and remove any residual heat before it has a chance to warm the roof deck.

3. Snow maintenance. Carefully remove the snow from the roof system, there will be no fuel to feed the ice dams.

   
   

The Significance of Ice Dams

Ice dams can cause damage to your home, including:

• Water leaks inside the house: Melted water can seep under shingles and into walls.

• Damage to roofing materials: Ice buildup can lift shingles and cause cracks.

• Gutter damage: The weight of ice can pull gutters away from the house.

• Mold and mildew growth: Moisture trapped inside walls promotes mold.

• Structural damage: Prolonged water exposure weakens wood framing and ceilings.

  
  
  
  

Signs You May Have Ice Dams

Knowing the warning signs helps catch ice dams early:

• Icicles hanging along the eaves, especially large or uneven ones.

• Water stains or discoloration on ceilings and walls, in particular where the ceiling meets the outer wall.

• Damp or musty odors in the attic or upper floors.

• Visible ice buildup along gutters and roof edges.

  
  

If you have questions or need help preventing ice dams, please call us for advice and solutions to protect your home from winter damage.