In order to prevent ice dams, you have to understand what causes them and why you should care. What may seem like a benign stain on the paint can be much more than you were thinking. It can be like tip of an iceberg and if you don’t address it, you could face costly repairs. But before you start throwing money at a problem, it’s important to understand what an ice dam is and what causes one to form.
Ice dams are caused by freeze and thaw cycles. As the snow and ice begins to melt on your roof, it freezes along the eaves. It then freezes when it gets to the edge of your roof (areas without heated space below it) and it builds up. As it builds up, it creates a little mound, or dam. That dam allows water to collect behind and eventually it backs up under the shingles and gets into your home.
Key Factors Contributing to Ice Dam Formation:
- Heat loss from your home’s interior
- Poor attic insulation
- Inadequate roof ventilation
- Temperature fluctuations during winter months
Ice dams form through a simple but destructive process. When your roof has inconsistent temperatures, snow melts at higher points and refreezes at the colder eaves. This cycle creates a barrier of ice that prevents proper drainage, allowing water to pool behind it.
Sometimes called ice and water shield, this membrane helps to prevent damage from ice dams
Prevention Strategies
The best defense against ice dams is a proactive approach focusing on three main areas:
Proper Insulation
- Maintain consistent R-value throughout your attic
- Seal all air leaks between living space and attic
- Ensure proper depth of insulation (minimum R-49 for northern climates)
Effective Ventilation
- Install sufficient soffit vents (for air intake)
- Maintain clear exhaust vents
- Ensure proper air flow from eave to ridge
Professional Solutions
- Improving ventilation so heat cannot build up in your attic space
- Consider heated roof cables in problem areas
- Implement proper drainage systems and keep your gutters clear of leaves and debris
Emergency Ice Dam Solutions
If you’re already experiencing ice dams, here are immediate steps to take:
Safe Removal Methods
- Use a roof rake to remove snow (while standing safely on the ground).
- Create channels in the ice to allow water drainage.
- Use calcium chloride to melt ice instead of salt as calcium chloride will not damage aluminum. You can fill a nylon stocking with calcium chloride and hang it perpendicular to the ice dam. This may look ridiculous like nylon icicles, but it allows water to follow a path of least resistance toward the outside of your home instead of backing up into your home. An easy tip is to attach a rope to the end of the filled nylon, toss it up onto the roof and then pull it down until you just see the edge of the nylon. You can leave the rope dangling which makes it easy to remove once you have used this method to gently break through an ice dam.
Warning Signs to Watch For
- Icicles forming along eaves
- Water stains on interior ceilings
- Ice buildup in gutters
- Water dripping inside walls
Long-Term Protection
Invest in permanent solutions to prevent future ice dam formation:
- Professional roof inspection and maintenance
- Upgraded attic insulation
- Installation of proper ventilation systems (active ventilation is typically more effective than passive ventilation)
- High-quality ice and water shield installation