Icicles and Ice Dams on Roofs
After a long cold winter, and just as the temperatures get back to near freezing you’ll start to see icicles hanging on gutters and roofs. An ice dam or icicles hanging from the edge of a roof or gutters can not only cause damage to the roof it can also leak into walls causing damage to the interior of a home or commercial building. Icicles and ice dams are caused by too much warm air or moisture leaking into the attic making the attic warm. When you have snow on the roof and warm temperatures in the attic the snow starts to melt in the warm areas. The temperature outside is below freezing so the ice dams and icicles form at the colder edges of the roof. The only way to prevent ice dams is to seal up the warm air leaks into the attic.
Damage from ice dams leaking in walls, ceilings, sheetrock and interior areas of your home may be covered under your home owner’s insurance policy. Most damage to your roof or shingles is not covered by home owners insurance and is categorized as caused by improper home maintenance. It’s best to call your insurance company to find out if damage from ice dams is covered under your insurance policy.
The most common causes of ice dams and ice on roofs:
- Dryer vents that exhaust into the attic
- Bathroom fan exhaust vents
- Light fixtures
- Holes and gaps around cable or electrical wiring
- Exhaust from appliances such as stoves
- improper insulation depth
- Poor insulation around vents or plugged vents
- Attic entrance hatch leaks
I spoke with Nathan France from Kiser Construction, Inc. in Minnesota who shared some facts with me as well as some cautions when dealing with ice dam removal. Nathan has been working on ice dams for over a decade and he shared some very interesting stories with me which I have condensed in the never do these things to fix an ice dam paragraph below.
How to fix Ice Dams?
- Call a professional contractor who has done this before with a license to safely remove and clear snow and ice from your roof. Licensed professionals have the proper equipment and tools to melt ice dams without damaging your roof. Ice Dam removal experts charge about $150 an hour and the average home takes about 3-4 hours but you’ll be assured that the job is done right.
- Seal all air leaks in your attic to prevent warm air and moisture escaping into your attic.
- Have a blower door test and an infrared heat device test on your home to detect any leaks you might have missed.
Never do these things to fix an Ice Dam:
- Do NOT attempt to shovel the snow off the roof, you are likely to fall off the roof or damage the roof shingles. One of my neighbors used an electric shovel to get the snow off his garage roof. Next spring I saw gouges in his shingles and the roofing contractors had to come replace his whole roof. The best advice is to stay off the roof!
- Do NOT let any contractors, neighbors or family members on your roof that do not have a license or bonding to do this kind of work. If you let an uninsured person on your roof your home owners insurance will not cover an accident or claim.
- Do NOT attempt to remove ice by using tools on your roof like ice picks, axes, hammers, blow dryers and shovels. These cause damage to your shingles.
- Do NOT use rock salt in an attempt to melt ice dams. This method will cause more damage to your shingles and eves than you can imagine.
- Do NOT attempt to dump hot water on the ice to melt it as it may backup into the eves and cause more damage to the exterior or drip down into the interior of your home.
In the spring you’ll want to do a full inspection of your roof and any area that may have been damaged by water infiltration. The ultimate way to fix a ice dam is to seal up all the air holes and insulate with spray foam roofing.
EnergyStar recommended Levels of Insulation for wood structure buildings EnergyStar
Owens Corning Attic Insulation Guide includes insulation estimation calculator, insulation glossary, insulation installation videos, and lots of other good information. Owens Corning
University of Minnesota Ice Dam fact sheet U of M Ice Dam Fact Sheet
Minnesota Blue Flame Gas Association types of insulation and where to install insulation. Where to install insulation