Ice dams are your home’s worst enemies during the winter season. An ice dam is a continuous ridge of ice that accumulates at the edge of your roof. You can see it in the form of icicles that hang down from the roof margins. However, the problem begins during the warmer winter days, when the ice begins to melt. The ice block prevents the water or molten ice from draining off your roof. As a result, the stored water may seep into the shingles, leak into your house, causing immense damage to the ceiling, walls, paint, drywall, insulation, and other components.

What Causes Ice Dams?

ice dams

Ice dams occur when heat escapes into your attic or the warmer, higher part of the roof, melting the gathered snow on the roof surface. This molten snow then goes to the lower, colder roof area and freezes again to take the form of an ice dam. Some of the factors that determine ice dam formation are the architecture of your house, ventilation, insulation, and weather conditions. Ice dams are usually more severe after a heavy snowfall, mainly due to the inherent insulating properties of snow.

How Can You Prevent Ice Dams?

Any long-term solution to prevent ice dams involves not allowing heat to enter the attic and installing ventilation under the roof to keep it cold. In simple words, the exterior temperature of the roof must be the same as that of the underside of the roof. You can ensure this by following three simple steps:

Close Off Any Heat Outlets that Lead to the Attic

In maximum houses, most of the heat loss occurs via the ceiling into the attic. Therefore, seal off any unblocked walls, drywall gaps, and cracks on the ceiling due to elements such as light fixtures, plumbing pipes, chimneys, or access hatches — which are causing air leakage. Some of the measures you can take to stop air from leaking are fixing the insulation and covering leaks with foam or caulk. However, carry out these actions only during winter, otherwise, your attic will turn extremely hot during the summer months.

Check Your Attic Insulation Depth

Calculate the levels of your attic insulation. According to standard building codes, you should install around 12 to 14 inches of fiberglass or cellulose. If you find that your insulation depth is less than 8 inches, add more of it to your roof. Go for blown-in cellulose and fiberglass as your insulation materials, because they fit securely around obstructions and leave minimal gaps. We would suggest hiring a professional for this job because the task is not an easy DIY project.

Read more: Home insulation guide

Install Roof and Soffit Vents

The purpose of attic ventilation is to maintain the temperature inside by drawing in cold air from the outside and blowing out warm air from the interiors. For your ventilation to function properly, you must ensure that the minimum size of the openings is approximately one square foot of vent per 300 square feet of ceiling or attic floor area.

Ventilation facilitates a continuous flow of air from the soffit or underside of roof eaves to the roof edge. Installing a soffit-to-ridge ventilation system along the length of your house is the best option to cool the roof surface. Here, insulation baffles are installed at the lower part of the roof and over the exterior walls.

Additional Measures to Prevent Ice Dams

Fix a Heat Tape

You can install an electric heat tape — a high-resistance wire — so as to prevent ice dams when there’s a light snowfall. However, in areas where there’s heavy snowfall, heat tapes can further complicate the situation. It will just result in the ice dam moving further up the roof. This especially happens when your gutters are not clean and blocked by fallen leaves or other debris. Install the tape properly so that it circles around the complete roof edge, runs inside the gutter, and goes down into the downspout. Otherwise, the molten ice will refreeze in the gutter or downspout and clog them.

Use a Roof Rake

After a heavy snowfall, remove the gathered snow with the help of a rake. This is an immediate course of action. When you remove the snow, there is no scope for the snow to melt and form ice dams. Be careful when you carry out this activity. Don’t stand on a ladder and start cleaning! We would recommend performing this task only when you live in a single-storey house. Also, be careful not to damage the shingles which are quite brittle during winters.

Clean the Gutters

Before the snow starts falling, clean your gutters and downspouts. This step will ensure that the molten snow has an outlet, minimizing the risk of ice dam formation.

Read more: Rain gutters cleaning maintenance guide


Ice dams alone don’t create any problem. The damage is caused mainly due to the seepage of water into your ceiling and walls. If you do face the problem of ice dam formation and leakage thereafter, we would advise you to hire a professional roofing company. They will use a steamer to melt the ice away without damaging your roof.

Read more: Preparing home for winter insurances

What Are Ice Dams and How to Prevent Them? was last modified: September 15th, 2022 by Anisha Dutta
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