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What is an ice dam on your roof? How can you tell if one exists, and what can you do about it once you know one is present? In the severe winter weather in Minneapolis, these questions have all likely crossed your mind at least once.

Ice dams have caused over 50 million dollars in damages to homes in the Minneapolis area in just one winter, so even though insurance will not cover their removal, it’s a good idea to know what they are and how to identify them before they are allowed to sit and cause more expensive damages to your home over time.

In this article, we will be discussing what ice dams are, how they are formed, how to identify, prevent, and control them. Hopefully, this information will help you keep your roof and the rest of your home in good condition, and help you make certain that your home is properly prepared for winters to come.

What Is an Ice Dam on Your Roof?

So, what is an ice dam on your roof? An ice dam is a ridge of ice that forms on the edges of your roof causing water to back up behind it and cause damages to your home. An ice dam is formed when uneven roof temperatures cause the snow to melt and freeze again on colder areas of the roof.

 Ice dams can form in as little as 24 hours, with as little as one inch of snow, and left to worsen, they can lead to severe damages to your gutters, weakened or loosened shingles, and eventually cause water to leak into the walls and ceilings inviting mold and mildew, which can lead to serious health problems.

How Do Ice Dams Form?

Ice dams form when uneven roof temperatures cause snow from the upper part of the roof to melt and run down the slope of the roof to the roof’s edge where the temperatures are below zero and freeze near the edge of the roof creating an ice sheet or “dam”. If you’ve ever seen an entire edge of a roof with icicles hanging off of it, that was because of an ice dam.

Tips to Prevent Ice Dams

With ice dams causing millions of dollars in damages to roofs in the Minneapolis area every winter, it’s important to know how to protect yourself. This next section will give you a better understanding of the four main causes of ice dams on your roof, and give you some helpful tips on how to prevent them from forming in the first place.

If you would like a professional opinion about your home’s current condition at any time, please remember that our expert inspectors are only a call away! You can call us during normal business hours at 651-703-2336, or if you need help right away, you can fill out our contact form by clicking the button below and we will get back to you promptly to discuss your concern. 

Four Main Causes of Ice Dams (Video)

The Four Main Causes of Ice Dams

There are a number of factors that work together to form an ice dam on your roof. The main factors that cause an ice dam to form on your roof are namely; snow, heat, and cold. However, there are factors inside of the home and attic that start the actual process that you should be aware of.

Here is what you should inspect to prevent ice dams:

• Uneven Heating – A number of issues could be causing uneven heating in your home, including leaking duct connections, leaking return vents, damaged or fallen insulation, kinks in your ductwork, leaks in your filter slot area, and rugs or furniture covering your air conditioner vents.

• Improper Roof Ventilation – Improper roof ventilation is caused by either deteriorating insulation, damaged shingles, or rusting attic fasteners.

• Improper Insulation – Improper insulation can cause moisture buildup in your attic, and when allowed to sit for long periods of time can cause rust, roof damage, and mold and bacteria.

• Heat Loss by Air Leakage –Air leakage occurs when air from outside enters your home and your conditioned air escapes, resulting in poor indoor air quality. Air leakage also can contribute to moisture problems and further damage or health issues if left for too long.

Ice Dam Prevention Checklist

To prevent ice dams from forming, the goal is to make your roof is an even temperature all the way across. Start off by making sure that your ceiling is airtight so that no warm, moist air can flow from the inside of your house into the attic.

Also, consider adding an extra ceiling or roof insulation to cut down on heat loss by conduction. Increasing ventilation, adding extra insulation, and sealing off any possible air leaks that might heat up the underside of the roof are all excellent ice dam prevention measures that you can take to ensure a safe and damage-free winter.

Here is a helpful checklist that you can use to make certain that your home is winter-ready and no ice dams will damage your home:

1. Ventilate Eaves And Ridge – A ridge vent equipped with continuous soffit vents will circulate cold air under the ridge of the entire roof. Both soffit and ridge vents should have identical size openings and leave at least 1 sq. ft. of opening for every 300 sq. ft of attic floor. Baffles should be placed at the eaves to allow a clear path for the airflow from the soffit vents.
2.  Exhaust Vents – Check to make sure that ducks coming from kitchen, bathroom, and dryer vents lead outdoors through either the roof or the walls. These vents should never exit through your soffit.
3. Add Insulation – Adding more insulation on the attic floor will keep the heat inside where it belongs. If you are unsure about the type and amount of insulation that you should use, feel free to call us or fill out one of our contact forms to set up a free assessment.
4. Make Sure the Hatch is Capped -Leaving the attic hatch unsealed or a whole-house fan open leaves the attic very vulnerable to uneven heating because, during the winter, they are just large openings for heat to escape. The openings of your hatch or fan should be capped with weather stripped caps, which can easily make out of foil-faced foam board and then held together with aluminum tape.
5.  Replace Old-Style Lights -Replace any old-style recessed lights with sealed “IC” fixtures. The old-style recessed lights give off great plumes of heat and generally can’t be insulated without creating a fire hazard, and the “IC” fixtures can be covered with insulation.
6.  Flash Around Chimneys -Make sure that there is L-shaped steel flashing held in place with unbroken beads of a fire-stop sealant around Bridging the gap between the chimney and house framing. Use canned spray foam so that the insulation is fire safe.
7.  Seal and Insulate Ducts -HVAC ducts and exhaust ducts should be covered entirely with R-5 or R-6 foil-faced fiberglass.
8.  Caulk Penetrations -Seal any entry points for electrical cables and vent pipes with fire-stop sealant. Also, keep an eye out for any spots where light shines up from below or the insulation is stained black from dirt.

How to Control Ice Dams

There are several measures that you can take to control ice dams on your roof once you have identified that one exists. Using a “roof rake” and/or push broom to remove snow from your roof that accumulates during the winter will eliminate one the main ingredient necessary to form an ice dam, but you could end up damaging the roofing materials. Using a hose to apply tap water to the dam on a warm day works fine also, just work upward from the lower edge of the dam until it is removed.

If you find yourself in an emergency situation where water is leaking into the house, make channels in the ice dam to allow the water behind the dam to safely drain off the roof. However, this channel will only be effective for a few days and is only a temporary solution to ice dam damage

What Is an Ice Dam on Your Roof?

Hopefully, this post has answered your question, “What is an Ice Dam on Your Roof?” and also helped you to prepare for, identify, and control ice dams on your roof in the future. If you have any questions regarding ice dams or any other type of winter damage to your home, our friendly expert storm damage inspectors are always just a call away.

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