Last year ice dams seemed to be a plague of biblical proportions. More homes than I can remember in the last 15 years had leaking due to this problem. I want to explain how they form and what is the best way to keep them from building up next year.

The Anatomy of An Ice Dam
The formation of an ice dam occurs because of unequal temperatures between the warm roof area over the home and the cold roof area over the eaves. The outside supporting wall between these two areas is called the “warm wall”. No matter how high the insulation “R” value is in a home there is always heat loss out the top of the roof. That heat rises and causes the snow to melt and run down to the eaves. Since the eaves are cold the melted snow from the upper roof freezes at the lowest point on the eave and ice builds up over the eave. Once it forms on the eave it develops until it reaches the warm wall, which is where our winter wonderland turns into a nightmare The water will not freeze above the warm wall so it remains stagnant behind the built-up mass of ice. At this point the snow continues melting and water pools as it is blocked from moving downward by the ice dam that has formed on the eave. The water, trapped behind the ice dam, starts to leak into the home. This creates a huge problem since roofs are designed to shed water, not hold it stagnant behind a dam of ice.

The only way to solve the ice dam problem is to equalize the temperature difference by either lowering the roof temperature over the home or raising the roof temperature over the eaves.

Cold Roofs:
The Greenest Solution To Ice Dam Problems
Cooling the roof temperature seems to be the most logical solution to an ice dam since it can be done passively and cost nothing to maintain or operate.

A cold roof is based on the science of airflow and the fact that hot air rises. The basic premise of a cold roof is that a second roof surface is built over the main roof and an unobstructed air space is created between the two roofs. This space allows air to flow freely inside this between the two roof surfaces. Since the hot air escaping from the home rises it creates a vortex and pulls cold air up through the cavity from the eave intake. When a cold roof is professionally designed the airflow creates a constant temperature on the upper roof surface that is close to the outside ambient temperature. As a result of this constant eave-to-ridge temperature, ice does not build up on the eaves.

In order to make sure that this system works each job must be designed specifically to the needs of that building. The amount of space between these two roofs will be different on each building depending on the pitch of the roof and how complex the roof design is.

Eave Heating Systems:
The Potential Green Solution To Ice Dam Problems
Most of us have seen heat cable running on the eaves of a home in a zigzag pattern. This is the least expensive way (considering the initial investment) to relieve the problem of ice dams. It is also admittedly the least attractive.

There are numerous products that cover up the cable to help give a cleaner appearance to the roof. There has been a lot of research and development in this area in recent years. The product I find most attractive and cost effective is The Green Melt Series by Ice Dam Management Corp. They have three products: Dyno-Melt (which uses Self-Regulating heat cable to generate heat), Hydro-Melt (which connects to your boiler system like your heated driveway) and Enviro-Melt (essentially the same system as Hydro-Melt but it is connected to radiant solar so like a cold roof it is completely passive). All three of these are covered systems that reach up past the warm wall and clear the entire eave not just the last few inches.

A beautiful home being built this year in Glenwild, The Waterhouse Project, has opted to utilize the Hydro-Melt system to ensure that the roof is kept safe from snow and ice. Since this home is being built to green standards as verified by Build Green Utah it was important to the owners that the eave melt system be as environmentally friendly as possible. After looking at numerous products Hydro-Melt was selected as the most cost effective and attractive option for this residence.

Midway City has opted for another way of solving their ice dam problems. They are re-roofing their old wood shingle roof with a metal shake made by Classic Metal Roofing Systems. In the areas where they have had problems with ice dams they are installing self-regulating heat cable under the dimensional metal shakes. This gives the appearance that there is no heat cable but, in fact, it is just hidden from site under the roofing panels. Ice Dam Management Corp. and Classic Metal Roofing Systems developed this installation method in a joint project. The result is a system that has a consistent look over the entire roof and yet it still heats the eaves and keeps the ice off. These two companies have worked out ways to use both heat cable and radiant tubes for either re-roof or new construction applications.

In Park City we build homes with 3 to 4 foot eaves. If the ice melt system is smaller than that the ice will form above the melt system and the ice dam will cause leaks as if there was no ice melt system at all.

With the use of the radiant heat option this system can deal with all of the problems that occur on an ice dam for about 15% of the operational cost of the old zigzag system or the most popular of the covered systems. Added to all of these benefits it also gives a great architectural style to the look of your home.

In our environment there are only two ways to solve the problems of ice dams. Long term it costs less to install a passive non-energy draining system like a cold roof. The up front investment for an eave heating system will be less but over time will cost more money to operate. As with any decision on your home this is not easy and there are many more things than I can address in this article that must be taken into account.

Not doing anything or having something done wrong will only result in damage to your home, your possessions and your nerves.

We cannot have a discussion about roof top snow and ice in Park City and not think about holding the snow on the roof. Many roofs in Park City are metal and the snow slides. I have learned over the years that your opinions about snow sliding off your roof depends on the type of roof you have and the design of your home. If your roof is metal and sheds over your garage or front entry, you may not think it is such a good idea to let snow slide. For the rest of you who have shingles or shake just trust me, they are right! Ice Dam Management Corp. has a great series of snow stops which are not only stronger then the most common stops used in Park City but they are far more attractive. Holding snow is a matter of keeping the whole area from sliding not just putting stops at the eave. A combination of engineering and experience can make sure that a roof top avalanche does not damage your property or worse.

Having worked with the problems of snow and ice in Park City since 1994 I am uniquely qualified to assist you in understanding the best system to deal with your roof top snow problems. Feel free to contact me for a free consultation regarding your ice dam nightmare!

To find out more about Nielco Roofing and Sheet Metal, Inc. go to www.nielco.net or call our Park City office at 435-200-0051 or Salt Lake office 801-263-0444. Dennis Duce can be reached at 801.656.8472 or by e-mail, dennisduce@gmail.com.