As Nebraskans, we’re used to the cold winter months. We know how to handle ourselves in ice, rain, sleet, snow… you name it! One thing you might not know, however, is what to do when you start seeing those large spiky icicles hanging from your roof. Did you know these icicles could be a sign of a much larger problem and could cause major damage to your roof and even the interior of your home?

Okay, wait. Now you have questions, right? “What kind of problems, exactly?” “Why do they happen on some houses and not others?” and most importantly “what can I do about it?” Don’t stress, we’re here to knock those questions out.

WHAT IS ICE DAMMING?

We’ve all seen them. Just take a look around Lincoln and Omaha right now. Basically, an ice dam is a built-up ridge of ice that can form at the edge of your roof. When snow packs up on your roof, the snow underneath the pack will start to melt from the heat your house is providing. This melt-water will then run down to the eaves and because eaves tend to be the coldest point on the roof, it freezes there. Once this happens, and more melt-water is continuing to try to run down the roof, the ice build-up grows.This is due to the obstruction of the initial ice that froze in the eave of the roof. As the melt-water continues to drip with nowhere to go, a water backup will occur and everyone knows: standing water on your roof=bad news.

Ice damming

Large Ice Dam

WHAT KIND OF PROBLEMS CAN ICE DAMMING CAUSE?

So now we know what ice damming is, but what does it do? That melted water will continue to freeze and back up but where does that water go when it starts to thaw again? If the materials on the roof are in poor condition (or possibly installed incorrectly) this can cause a serious problem. An ice dam could potentially cause a leak through your roofing material. This means possible damage to your walls, ceilings, insulation, and in some cases even the actual structure of your roof. Yikes!

Ice dam on an asphalt roof

WHY DOES ICE DAMMING HAPPEN ON MY HOUSE BUT NOT MY NEIGHBORS?

To put it simply, ice damming happens on warmer roofs. If your neighbor’s roof has proper insulation and ventilation, it can fight off ice damming much more efficiently. Ice damming will only occur when three things happen:
1) The temperature of the air outside is below freezing
2) There is heat coming from the house below the roof
3) There is a thick layer of accumulated dry snow.
Ice damming will not happen if only two out of three of those things occur. The conditions have to be just right. For example if the under-roof temp is above 30 °F and the outside air temp is below 22 °F and there is plenty of dry snow fall, you have a good chance of ice damming.

WHAT CAN I DO TO PREVENT ICE DAMMING ON MY ROOF?

The temperature in your attic should always be the same temperature as outside. If this isn’t the case there are usually only two reasons for that. The first is there is insufficient insulation and the second is usually due to poor ventilation. Proper ventilation is important in order to carry the escaping building heat somewhere else and helps to assure a cold roof surface. Keeping a cold surface will prevent that under layer of snow from melting in the first place and stop ice damming before it starts.

MY ROOF HAS AN ICE DAM, WHAT SHOULD I DO?

The most important thing is to be safe. Roof rakes and roof scrappers are common tools but can be dangerous to use and could potentially cause further damage to your shingles. If you are currently using a roof rake just remember the snow and ice must be scrapped off completely. Try not to stop half way up because if you do the ice dam will just re-form in the spot where you leave the snow and ice, causing more issues in other places. Using any other tools, such as a chisel, could cause more damage to your roof and is not recommended at all. Regardless of whether or not you are seeing any interior damage, the best thing you can do if you are seeing ice damming on your roof is to call a roofing professional for a consultation. A roofing expert should be able to get into your attic and identify if it is an insulation issue, a ventilation issue, or both and help you take the next steps.

Ice damming is an interesting phenomenon that Nebraskans get to experience often. Lucky us, right? Now that you know a bit more about those beautiful, but potentially harmful, icicles hopefully you are a bit more prepared for Mother Nature’s next go round. Keep an eye on J-Tech Construction’s Facebook page for more information on our upcoming podcast about ice damming. J-Tech’s Exterior Experts will go into further detail about different products, issues, and even talk a bit about city code and what you should expect from your roofing professionals.