You may notice that the home shown below has some icicles (sarcasm intended). Obviously, when something like this occurs, it is quite likely that you have ice dams as well as a giant insurance claim from the subsequent water damage it has caused. The fact is, the vast majority of the ice dam steaming projects we complete are not on homes with monster icicles. When we arrive we often see quite modest icicles from the ground. The relationship between icicles and ice dams is not difficult to understand when you study the problem for awhile. This Case Study digs into the topic of icicles and ice dam life cycles.
Do icicles mean ice dams? The short answer is NO. While icicles on the edge of the roof are often a precursor to ice dams, they are not always present when ice dams begin to cause leaks through a roof system. Ice dams and icicles are part of the same accumulation but they are not the same thing by any means. This brings us to the normal life cycle of an ice dam.
The characteristics of ice dams change over time. The typical lifespan of an ice dam rangers from a few days to a few weeks. During that time it may get thicker or thinner, icicles may appear and disappear on its’ leading edge, and it may be almost completely hidden under snow or partially or completely exposed. For this reason, there is a big different between a young ice dam and an old ice dam in terms of the presence of icicles. Very young ice dams often have visible icicles on their leading edge. Over the following days most ice dams tend to grow more in depth than thickness, meaning the ice migrates higher up on the roof plane (refer to Case Study #06 for more information). Icicles on more mature ice dams tend to melt away from the affects of direct sunlight or warmer outdoor temperatures. However, while the telltale icicles may be missing, the mass of the ice dam is left behind, frequently hidden under a blanket of snow.
The photos above (A) and (B) demonstrate this phenomenon on two St. Louis Park homes. Virtually no traditional signs of an ice dam and yet you see water leaking down the exterior wall, through the siding and in the wall cavity itself. Bad news.
Case Study #16 examines the important topic of ice migration, from icicles to the interior of your home.
The Relationship Between Sunshine and Ice Dam Formation
Ice dams happen when there is a section of roof that is above freezing (32°) where roof snow melts which then drains to an area that is below freezing, usually the eaves, where it refreezes. The source of this temperature differential is usually the result of interior heat loss, specifically via air leaks and insulation issues. In fact, according to our experience, 95% of our client’s ice dam problems can be mitigated or eliminated altogether through the modification of the thermal characteristics of the home. Still, we see ice dams on certain homes for reasons outside the scope of it’s architectural deficiencies. Homes with what we might call nearly perfect air-sealing, insulation and ventilation still get ice dams. This Case Study describes such a situation.
The winter sun hits Minnesota homes (and all homes in this latitude) at a low angle during the winter. The result is that certain roof slopes never see direct sunlight while others get hit quite directly. The above illustration demonstrates an ice dam situation that relates to the heating effects of the sun. Solar radiation warms the roof slope on the dormer (1), the resulting melt water drains to an area of the home (2) that never sees direct sunshine where it refreezes to form an ice dam (3). These are particularly challenging ice dams to prevent. Often times heat tape, also known as heat cables, are the only affordable option.
In my travels around Minneapolis today looking at ice dam prevention jobs, I noticed a number of homes that already exhibit signs of ice dams. To be more specific, I noticed water and ice coming down the siding and in through the eaves on a number of homes such as the one shown here. This represents a clear signal that water is backing up behind an accumulation of ice on the roof and going where it’s not supposed to go. Want more signs of ice dam issues, click here. With another snowstorm approaching on Christmas, I’m predicting that this might be another troublesome year for Minneapolis homeowners relative to ice dams.
Ice dam removal Minneapolis
What can you do? Unfortunately, once ice dams form and begin to cause problems, the only answer is to have them professionally removed. We use true steamers, machines that superheat water to steam. How do you tell the difference between a high temperature pressure washer used by competitors and a steamer? It’s simple. Does the gun have a trigger or not? If it has a trigger, it is simply NOT a steamer. IDSAFE, a unique organization whose entire purpose is to educate property owners on ice dam steaming, can be found here. The Ice Dam Company is a proud member of IDSAFE. All of our machines have been verified to meet the standards of true ice dam steamers, unlike two of the largest ice dam removal companies in the Twin Cities. (You know who you are!).
Of course the better answer to ice dam removal in Minneapolis is ice dam prevention. We engage in more ice dam prevention work than anybody in the United States, employing both architectural solutions and non-architectural solutions which includes heat tape and heat cable, insulation, roofing, remodeling and general home performance inspections.
Our sister company, Kuhl’s Contracting, engages in the hundreds of attic insulation retrofits and reroofing projects every year in Minneapolis and surrounding communities to address the underlying causes of ice dams. Kuhl’s Contracting also installs heat cable and heat tape on commercial properties and residential properties all over Minnesota. We are proud to sell HeatTapePro, made by Radiant Solutions Company, a premium self-regulating commercial grade heat cable available on a number of online retailers including Amazon. HeatTapePro can also be purchased at The Heat Cable Store, an online direct-to-consumer website that sells a number of heat cable and heat tape products by different manufacturers. Of course, you may also buy HeatTapePro here, at The Ice Dam Company Store.
Click hereto schedule an appointment with our ice dam removal or ice dam prevention teams.
Ice Dams on Mansard Roofs Can be a Seriously Big Headache to Remove
Roof Styles Affect Ice Dam Severity
As discussed in Case Study #16, there can be some serious problems if homeowners decide to remove snow from only a portion of the roof plane affected by ice dams. We call it the ‘Double Dam’, which refers to the fact that ice dams can grow much further up the roof when only lower sections of snow are removed (commonly done with roof snow rakes because they can’t reach high enough on the roof).
Mansard roofs, such as this one from Edina, Minnesota, can create massive ice dams when the steep pitch (B) is cleared of snow. This is amplified when the slope has directional bias towards the north because the sun will not help melt the ice as it accumulates. In the photo, below, we see two ice dam problems on this Edina mansard roof. The traditional location (A) is exacerbated by the low roof pitch (Case Study #09 explores the relationship between roof pitch, or roof slope, and ice dams). Area B has an ice dam that covers the entire span of the roof slope. This took many hours to remove even with our commercial ice dam steaming equipment.
Which Ice Dam Do You Want?
Ice dam #1 is not the one you want. Ice dams like this take hours to remove with steam, which is the most efficient and safe method for removing ice dams. This ice dam is thin but it has grown many feet up the roof. Ice dam #2 is an easier problem to resolve.
How Roof Pitch (Roof Slope) Affects the Impact of Ice Dams on Standard Residential Construction
Fact: The Flatter the Roof, the Less Ice it Takes to Cause Problems
As discussed in previous Ice Dam Company blogs and Case Studies, there is a strong relationship between roof slope and the timing and likelihood of damage as the result of ice dams. Specifically, low roof slope areas are far more susceptible to damage by small ice accumulations than areas of steeper slope. Why? It comes down to basic geometry. Study the diagrams, below. You can see that the high slope roofs (C) require a pretty thick ice dam to form before water will begin leaking into the home. Eave depth plays another important role. See Case Study #10 for more information.
Ice dams create leaks when melted water from higher on the roof slope hits a dam of ice and is forced to travel backwards, up and under the plus of the roofing system (typically asphalt shingles). When that backward motion occurs outside the plane of exterior wall (dotted red lines in diagrams), the water runs down the exterior wall or through the soffits (zone indicated by happy face). As soon as the water falls on top of the top plate of the wall it seeps down through the wall causing damage to insulation, finishes and flooring (zone indicated by sad face). Truthfully, water coming through your soffits is nothing to be happy about. The next step is the interior of your home so it is considered an emergency in terms of the progression of the ice dam. As mentioned before, if you see ice coming through the soffit or down the exterior wall, it’s time to get that ice dam removed.
Wayzata Residence with Low Pitch Roof Suffers the Consequence
Seen below is a home in Wayzata, Minnesota where we steamed an ice dam a couple of years ago. The construction assembly was typical 2×6 walls, 12″ eaves, 6″ facia with a 2/12 roof pitch. From the ground, no ominous, threatening icicles could be seen, just a couple of pathetic whiskers of ice off the face of the gutter through the soffit (D). Pan out and you see that the entire exterior wall was bleeding ice through the siding. This is bad. This home had massive damage to the interior insulation, drywall and flooring systems.
As discussed in Case Study #06, low pitch roofs also tend to create ‘deeper’ ice dams (E), where the ice has grown further up the roof. Deep ice dams take far longer to remove.
No icicles does not mean no ice dams.
Low pitch roofs present higher risks in terms of how quickly small ice dams can cause big problems.
Ice or water coming down the exterior wall in below freezing conditions is bad. Very, very bad.
How Much Should it Cost to Have an Ice Dam Removed: Ice Dam Steaming Costs Explained by The Ice Dam Company
Ice Dam Removal: Pricing Vs. Cost
As mentioned in Case Study #05, there is a big difference between price and cost when trying to figure out how much your ice dam removal project will cost. The price is what someone tells you over the phone, normally relating to what they charge per hour for their ice dam removal services. We made a list of the 8 most common factors in determining the cost of ice dam removal in Case Study #05. Here is an examination of one major driver in ice dam removal cost: The depth of the ice dam.
Which takes longer to remove?
Intuition might suggest that thicker ice dams (A) take longer to remove then thinner ice dams (B). Not true. The main factor in the ice dam removal cost is how far up the roof the ice has grown. We refer to this as the ‘depth’ of the ice dam. Deeper ice dams take much longer to remove than those that are thick but shallow.
Estimating the Cost of Ice Dam Removal by Steam
You might think that after having removed thousands of ice dams around the country over the past 25 years we would be able to provide an accurate estimate over the phone as to how long a project might take. Sadly, we can’t. Anyone offering a guaranteed timeframe for ice dam removal projects over the phone is frankly full of it. We know that we can often remove between 10-15 feet of ice dam as measured along an eave every hour after the equipment is set up (C), below left. We know that there are many factors that determine the ultimate length of the ice dam steaming time, as discussed in Case Study #05. One of the main project timeframe drivers is ice dam depth and it can not be known until an experienced eye sees it and that can’t be known until the snow has been removed from the area. Until the ice dam is fully exposed it is impossible to know how long it will take to remove it. In the photos below, the ice dam on the right took three times longer to steam off than the ice dam on the left, even though it was 1/3 the thickness and the roof was a ‘walker’. It’s all about how far up the roof the ice has grown.
We have spent a lot of time discussing the finer points about ice dams over the years. This Case Study is about pulling the focus back to the most global understanding of why ice dams happen.
What Causes Ice Dams
There are over a dozen factors that contribute to the formation of ice dams, all of which have been discussed in previous Case Studies. Fundamentally, only one condition MUST be met in order for ice dams to form: A temperature differential from one area of a roof assembly to another area, with the upper area being above 32° and the lower area being below 32°. See below.
How it Works
This diagram demonstrates the basic concept behind ice dam formation. Snow melts in the area above 32°, water runs down to the area below 32° and refreezes. This cycle continues until an accumulation of ice forms that is large enough to block water from flowing naturally off the roof. The resulting ‘ice dam’ forces water to back up under the roofing materials and into the structure. There are many intersecting variables that cause the phenomenon described here. See below.
List of 7 Contributing Factors to Ice Dam Formation
A period of outdoor temperatures ranging between 0°-10° at night followed by daytime temperatures between 10°-20°.
Repeated snow falls that keep the roof loaded with new snow resulting in at least 6″ of coverage at all times.
Thermal inefficiencies in the home that allow warmth to heat up the roof deck from the underside.
Homeowner lifestyle that results in excessively heated spaces (More heat equals more roof snow melting).
Roof pitch: Flatter roof pitches tend to be more affected by problematic ice dams.
Eave depth: Smaller eaves tend to be more affected by problematic ice dams than deeper eaves.
Age and construction style of home: Older homes tend to be more affected than newer homes.
I’ve been working on a new graphic to describe the basics for homeowners in Minneapolis to identify a problematic ice dam. It’s true that some ice dams cause no problems. The key consideration in determining whether or not an ice dam is a current problem is all about where you see ice. Study this drawing closely and you will see that any ice behind the facia is a bad sign. Ice through the soffit, down the exterior wall or through the window frame is very bad thing. Leaks caused by ice dams minneapolis
Removing Ice Dams in Minnesota: We Serve Many Areas in the Minneapolis Metro
The Ice Dam company based out of Hopkins, Minnesota, about 5 miles west of Minneapolis. We've done gutter ice removal, roof ice removal and ice dam removal all over the Twin Cities, on new houses and old ones.
Some of the more frequent places we've done ice dam services are: