Ice dams: Why They Form and How to Prevent Them


Icicles may look pretty, but if they form on your home’s eavestrough, the truth about these icy shards is chilling. 

Why Ice Dams Form

Ice dams form when warm air from inside your home escapes through your attic roof due to poor insulation and possibly ventilation. The warm air will melt any snow on your roof. The melted snow, or meltwater, will run down to your eaves where the surface temperature is colder. The colder surface will cause the meltwater to pool and refreeze, creating a drainage barrier, or ice dam.

When Icicles Are Dangerous

Small icicles that form on your gutters during brief melting periods are not a concern. However, when icicles grow, this indicates a problem. Other ways to to tell if you have an ice dam problem are:

  • water-damaged ceilings
  • wet insulation
  • sagging or collapsed ice-filled gutters
  • water that drips and freezes down the exterior of your home

How to prevent ice dams

To prevent ice dams, air leaks in the attic/roof need to be sealed. An effective way to stop inside air from reaching the roof is to upgrade your insulation to XCELUS spray foam.  The expanding foam insulates and seals cracks and gaps in one step, ensuring that warm air is prevented from reaching the roof. As an added bonus, you may realize savings of as much as 15% on heating and cooling bills.

Take the chill off of your monthly energy bills. Insulate with XCELUS spray foam insulation.