What Are Ice Dams and How Do They Damage Utah Roofs?

If you have lived in Utah through a few winters, you have probably seen those thick ridges of ice hanging off the edge of a roof. Maybe you have seen them on your own house. They can look kind of impressive, honestly. But what is happening behind that wall of ice is not impressive at all. It is water backing up under your shingles and finding its way into your home.

That is an ice dam. And it is one of the most common causes of winter roof damage along the Wasatch Front.

How ice dams actually form

Here is what happens. Heat from inside your home rises into the attic. If your attic is not properly ventilated and insulated, that heat warms the roof deck from underneath. Snow sitting on your roof starts melting from the bottom up. The meltwater trickles down the slope of your roof until it reaches the eaves, which are colder because they extend past the heated part of your house. The water refreezes right there at the edge. Over time, more meltwater builds up behind that ridge of ice with nowhere to go.

That standing water works its way underneath your shingles. Shingles are designed to shed water running downhill. They are not designed to hold back a pool of water pushing uphill. Once that water gets under the shingles, it soaks through the decking and into your attic, your walls, your ceilings. I have seen ice dam damage that rotted out entire sections of roof decking. I have seen it destroy drywall, warp hardwood floors, and create mold problems that cost thousands to fix.

Why Utah is especially prone to ice dams

We get the perfect combination. Heavy snowfall followed by sunny days in the 40s and 50s. That is textbook ice dam weather. The snow melts during the day, refreezes at night, and the cycle repeats. Homes in the benches and east side neighborhoods are often hit hardest because they get more snow accumulation, but I have seen ice dams on homes all across the valley.

Older homes tend to be more vulnerable because they were often built with less attic insulation and ventilation than modern building codes require. But I have seen newer homes with ice dam problems too, usually because something was not done right during construction.

What if you already have ice dams

If you are dealing with ice dams right now and seeing water stains on your ceiling, the first thing to do is not panic. Call a professional. We can assess the situation, help you manage the immediate problem, and then talk about what needs to happen to prevent it from coming back.

Roof raking, which means pulling snow off the lower few feet of your roof with a long-handled rake, can help in the short term. It removes the snow before it has a chance to melt and refreeze. But it is treating the symptom, not the cause. The real fix is making sure your attic ventilation and insulation are doing their jobs.