First, what is an Ice Dam? An Ice Dam is a ridge of ice that forms along the edge of your roof, preventing the melted snow from running through your gutters and away from your house. If the water cannot drain through it’s proper channels, it will eventually find its way into your home.
What causes Ice Dams?
The house’s attic is under insulated. The building material used back in the day doesn’t compare to today’s materials. Most homes built before 2000 have only the bare minimum when it comes to attic insulation (R-19). The updated Michigan building code for attics now a days is R-38. This is a difference of almost 10-14 inches on insulation! Now if you keep your home at a comfy 72 F and have the bare bones minimum insulation in your attic, than you are asking for Ice Dams. If you remember what you learned in science class, heat rises and when the heat in your living spaces in your home rises through the ceiling and into the attic, your attic will become warm. So, heated attic space + frozen snow on the roof = melting snow. This melting snow will dam at the gutter and your home will take on water damage.
Roof Ventilation is not correct. You may have saved thousand’s using Uncle Tom’s roofer last summer, but Tommy Boy may have ended up costing you more in the long run. Every builder and roofer that holds a licence in their trade knows the importance of roof ventilation. Every roof and attic needs good airflow. Good air flow comes from an intake and outtake. If your home has an overhang at the roof’s edge, than you are probably aware of the soffit vents. These vents are your roof and attics intake. These should be cleaned out time to time so birds and squirrels don’t nest in them and prevent good intake air. A lot of homeowners are upgrading their roofs with ridge vent these days. Ridge vent is installed at the ridge of your roof and acts as the outtake. These systems work great so both the intake and outtake are free and clear of debris.