What is an ice dam? It isn’t something that’s made by ice beavers. It is a ridge of ice that accumulates on the edge of a roof. Equally true to both halves of its name, an ice dam prevents meltwater from freely running off the roof – and that can cause many problems for a homeowner.

We’re going to explain why an ice dam damages the underlying property, as well as how you can put a stop to one. But first, let’s explain what causes an ice dam to form in the first place.

 

What Causes an Ice Dam?

An ice dam requires two conditions to arise: snow accumulates on a roof, and the roof’s surface isn’t a uniform temperature. When an ice dam forms on a section of a roof, the surface above it is above freezing; the surface beneath it is below freezing. Snowmelt runs down the roof until it reaches the freezing surface, at which point the water solidifies to create the ice dam.

Why would a house’s roof be different temperatures to begin with? It could be because the roof has air leakage or is incorrectly insulated, and therefore allows heat to escape unevenly.

Alternatively, a heating duct, light fixture, chimney or exhaust vent may warm a section of roof while leaving a section beneath it frozen.

 

How Does an Ice Dam Cause Damage?

An ice dam’s destructive potential arises from its ability to trap liquid water just above itself. Unfortunately, water necessarily follows the path of least resistance. Rather than remain harmlessly on the roof, water seeps into any cracks and crevices beneath itself and continues to flow downward.

Water infiltration can damage your home in a number of different ways. Water can saturate the insulation until it becomes no longer effective at retaining heat. It can weaken the roof decking, structural beams and rafters until they are no longer capable of bearing sufficient weight. It can also cause the paint inside and outside your house to blister.

Perhaps worst of all, water infiltration can create ideal breeding conditions for black mold. The fungus won’t just make your walls and ceilings look hideous. Its spores can cause respiratory problems like coughing and sneezing in addition to irritation of the eyes. In extreme cases black mold causes mycotoxicosis, which may produce severe illness in infants, the elderly, and people with compromised immune systems. Black mold may even weaken walls and ceilings until they are at risk of collapse!

An ice dam may damage the exterior of a house as well. The blockage typically isn’t completely effective at preventing meltwater from sloughing off a roof. Instead it permits a steady trickle, which allows the formation of unusually large icicles. Such heavy icicles can easily rip gutters

free from the fascia, which leaves the house’s foundation vulnerable to water infiltration (and obviously doesn’t do any favors to gutter system or fascia, either).

 

How Do You Prevent Ice Dams?

Raking the roof after every snowfall is an effective way to prevent ice dams. As we explained earlier, formation of an ice dam requires two preconditions: snow, and uneven roof temperatures. In other words, no snow, no ice dam! But if you do use a roof rake, take great care not to scrape so violently that you damage any of your roof’s shingles.

Spreading rock salt on your roof will remove ice dams. This approach is generally inadvisable, however, as the highly corrosive substance will also damage the roof, siding, gutters and downspouts, as well as kill any plants surrounding the home.

Heat cables are another popular solution for ice dams, although they are far from perfect. Heat cables can cause fires, expend over $5 worth of electricity daily, and look ugly. Worse yet, they often fail to serve their only purpose.

The best solution to preventing ice dams is to keep your roof uniformly cold – and accomplishing that revolves around installing adequate insulation and ventilation. Insulation will prevent heat from accessing the attic where it can warm the roof unevenly; ventilation achieves the same purpose. Together, insulation and ventilation should prevent any snow that gathers on the roof from melting.

The lasting approach to ice dam prevention entails several other steps, including sealing the attic hatch, rerouting exhaust systems so they no longer vent to the soffit, installing chimney flashing, caulking leaks, sealing ducts, ensuring that light fixtures aren’t releasing excessive heat into the attic, installing an ice and water barrier, and performing any repairs needed to return the roof to its best condition. Needless to say, that’s a lot of work, which is why many homeowners prefer to hire contractors when they wish to eliminate ice dams from their roofs.

If an ice dam should appear on your roof or downspouts, Contact Gilk Plumbing, Heating & A/C today! We will steam remove your ice dam to prevent further damage to your building’s structure. Don’t wait, as ice dams may appear pretty on the outside, they are causing continuous damage under all the ice. We service Albany, Avon, Cold Spring, Eden Valley, Freeport, Kimball, Lake Henry, Paynesville, Richmond, Rockville, St. Joseph and Watkins, Minnesota!