what is an ice dam?

What Is an Ice Dam?

An ice dam is that ridge of ice that forms along the edges of your roof in the winter. They can be a health hazard in some rare instances, but more importantly, they prevent ice from melting and draining off of your roof. In turn, that can cause the structure of your roof to falter from all the weight of the snow.

In this article, we thought we would explain all that you need to know about ice dams. How they form, why they are a problem, and how to prevent them. Let’s take a look:

Why Do Ice Dams Form?

The most common reasons are poor insulation and lack of good ventilation in the attic. That causes the roof to heat more than it should and the snow to melt. You would think that this is a good thing, but if the snow melts more than it should, then the excess water will easily collect in the drains. That water will quickly freeze again and create the aforementioned ice dam at the edge of your roof. 

In addition, icicles will start to form at the end of the dam when it starts to melt in the day and then refreeze at night. 

The whole process of ice dam and icicle formation will repeat as long as the temperature is too low and more snow continues to fall. 

What Problems Do Ice Dams Cause?

When the dams form, the water that remains behind collects in a pool, and some of it freezes, keeping the dam from shrinking. A large part of it remains trapped behind the dam, and as the snow keeps melting, it adds to the pool.  

Now, that water tends to start going through the shingles of the roof. This causes moisture damage to the roofing, but it also causes water to get inside the attic. It can also seep through the walls, the ceiling, and cause structural damage. 

On top of that, the mere existence of ice dams adds unnecessary weight to the roof, which can cause damage as well. 

The solution here is not only to get rid of the dam by:

  • Removing the snow from the roof.
  • Create a channel through the dam so the water behind it will have a place to escape. 
  • If the day is warm, you can also hose off the water, some of the snow, and the ice from the roof.

However, you also need to prevent the ice dam from forming again. 

How to Prevent Ice Dams from Forming?

  • Make the ceiling air-tight so warmer air won’t be able to enter the house through the attic.
  • Improve the ceiling and roof insulation, so less heat is lost. 
  • If you’re in the process of building your house, make sure you are following the requirements for roof and ceiling insulation levels. Also, make sure you construct an effective air barrier through the ceiling, so no air from the house enters the attic and then seeps into the roof.
  • Block any heat sources that may be causing the higher temperatures in the attic.

The Bottom Line

All in all, this should be everything you need to know about how ice dams form and how to prevent them. If you require more help, feel free to get in touch with 1-800-HANSONS, as we specialize in roofing replacement, installment, and ventilation.