What Are Ice Dams & Will They Always Damage My Roof?
Although seeing your house lined with icicles may look beautiful and majestic, almost like the gingerbread houses you created over the holidays, they can be harmful to your home. When snow or ice melts on a sunny winter day, the melted snow runs off to where the temperature is below freezing, thus causing the water to refreeze in the form of an icicle. As water continues to roll off your roof, the icicles grow in size. If warm air leaks from your living space into your attic, the heat can form a collection of melted snow to collect behind the icicles, causing potential harm to your home.

If you see lines of icicles hanging from the edge of your roof, be aware that it could be an indication of something called an ice dam. When heat from your home rises and gets into the attic space, it can melt the snow that is sitting on your rooftop. This melted snow will then run down the slope of your roof and refreeze at the edge, where the temperature is colder. An ice dam (a ridge of ice that forms at the edge of a roof and prevents melting snow from draining off the roof properly) can cause leakage into your home and therefore damage to walls, insulation, ceilings and other areas.
Forms of Ice Dam-age
- Torn-off gutters
- Loosened shingles
- Backed up water on roof & in gutters
- Peeling paint
- Warped floors
- Stained & saggy ceilings
- Soggy attic insulation
- Mold & mildew collection
Now that you know what ice dams can do, how do you prevent them?
- Make sure warm air doesn’t leak from your living space into your attic
- Seal any gaps or cracks in your attic space
- Add insulation to your attic floor to stop big heat leakages from the living space
- Be sure your attic is properly vented to allow adequate air circulation
- Use a roof rake to carefully remove excess snow from big storms to prevent heavy snow buildup
- Help to bridge the gap between your chimney and house by framing steel flashing around your chimney
- To slow a leak in your attic, try placing a box fan aimed at the underside of the roof where the water is leaking to help freeze the water in its tracks
As water backs up behind an ice dam, it can leak through the roof shingles if you don’t have a properly installed ice and water shield membrane. In reality, ice dams are not a big problem and usually cause no damage if you hired a professional roofing contractor and someone to insulate your attic up to par. If your roof was not properly installed and/or your attic area was not insulated correctly, backed up water from ice dams will enter your house and cause significant damage. So, it’s up to you to hire professionals to get the job done right the first time to prevent future damage.
The BEST Residential Roofing Contractor in Lancaster, PA
Best Contracting is one of the best residential roofing contractors in the Lancaster, PA region. Our highly-qualified, certified and dependable roofing contractors treat our customers like family. We specialize in a variety of types of commercial and residential roofing, siding and gutters and even offer a 10-year workmanship warranty.
We hope you found this information on ice dams helpful and now know how to prevent them in the future. If you find that your roof is in need of repair or replacement, contact us today at (717) 283-4524. Here’s to your roof keeping you safe and dry this winter!