It started with icicles that seemed somewhat festive, but as they have continued to grow, you’ve noticed dark patches in the snow on the roof where shingles are showing through. The snow is melting, but not evenly. And the icicles are still growing. If you’re not careful, you may develop ice dams on the roof—if they haven’t already formed.

What Is an Ice Dam?

If you live in a region that experiences snow and freezing temperatures, ice dams may form. An ice formation on your roof/gutter area that blocks freshly melted snow and rain from running off the roof. They develop when melted snow re-freezes before it can run off the edge. Depending on the weather, an ice dam can grow larger and larger, trapping more and more water on the roof’s edge until it causes water to leak into your home’s interior.

Ice Dams and Your HVAC System

Ice dams are a sign of a problem with a property's attic insulation or ventilation. Improper insulation and ventilation aren’t just a problem for a roof, they can cause unnecessary wear and tear on HVAC systems by making them work harder in the cold winter months.

What Causes Ice Dams?

Heavy snow and the winter sun can trigger the start of an ice dam. But other factors can make your home more susceptible to developing ice damming on the roof:

  1. Heavy snow buildup. With layer upon layer of snow on the roof, the likelihood of ice dams increases. The layer the sun melts will run into more snow, quickly cooling and refreezing it before it can run off the roof.
  2. Heat escaping through the roof. It’s normal to keep your home toasty warm during winter, but if the attic isn’t insulated well, the warm air will leak out the roof, causing the snow to melt quickly. As it runs into the gutter, the temperature will dramatically decrease, causing the water to freeze.
  3. Clutter in the gutter. If the gutter wasn’t cleared of leaves and other debris, or if snow and ice managed to build up, the water runoff would pass through several obstacles, slowing it down and increasing the chance of refreezing on the eave.

Related content: Spray Foam Insulation Can Save You Money

Why Worry About Ice Dams?

So, your house has large clusters of icicles and potentially a ridge of ice trapping melted snow on the roof. Is it a cause for concern? What damage do ice dams cause anyway?

The list:

  • Gutters and siding. As the weight of ice builds on the gutter, it can tear the gutter away from the house.
  • Roof. How do ice dams cause roof leaks? The melted snow (water) that gets trapped behind ice dams sinks into the shingles and refreezes, leaving the shingles heaving and damaged, and exposing the roof to leaks. If the damage is severe, the weight can cause your roof to sag or collapse.
  • Ceiling and drywall. Water that seeps through the roof runs down the ceiling and walls. This weakens the drywall and the water damage increases the odds of mold growth.
  • Insulation. As the intruding water runs through the ceiling and down the walls, it saturates the insulation. Wet insulation cannot effectively prevent warm air from escaping through the walls of a property. So you’ll have an ideal environment for mold growth in your walls. And have higher electric bills and decreased energy efficiency, too.

How to Prevent Damage from Ice Dams

After a heavy winter storm, many properties will be left susceptible to ice damming. Ice dam prevention is key to preventing winter damage to homes.

Here’s how to prevent ice dams on the roof:

  • Clear the gutters. Dirty gutters stop snowmelt from draining off your roof. Keep gutters clear to promote water movement.
  • Shovel or rake the roof. Roof raking prevents damage from the weight of snow buildup, as well as the potential water leaking into your home. (Never climb on your roof. Use a roof rake and consider hiring a professional to complete this task for you.)
  • Seal air leaks from the attic. Leaking warm air means more melted snow on the roof, which leads to a buildup of ice as it runs off the edge. Make sure your attic is properly sealed and vented.
  • Insulate your attic. Attic insulation prevents heat leaks that lead to uneven roof melting. A well-insulated attic means a cold roof and even melting.

Related content: Attic Ventilation Has a Role In Air Conditioner Efficiency

Does Homeowners Insurance Cover Roof Leaks From Ice Dams?

Insurance policies will vary based on a variety of factors including your location. Some homeowners’ insurance policies will cover damage sustained from the weight of snow and ice and even leaks from ice dams.

Insurance policies will not cover damage from potential negligence. Contact your provider to learn more about your coverage.

Prevent Ice Dams with Insulation

Clearing the gutter and shoveling the roof are effective measures, but if the attic is leaking heat, the ice dams will still come.

Life is busy enough. Hiring professionals to seal and insulate your attic will protect your home (and save you a lot of work) by stopping ice dams from forming.

Your local One Hour Heating & Air Conditioning offers skilled home and attic insulation services to keep your home cozy, save you money on utility bills, prevent unnecessary wear to your HVAC system, and reduce the occurrence of ice dams. Call (800) 893-3523 or schedule service online to get started.