As a home inspector in the Twin Cities, Mn area, I get a lot of questions about ice dams.
Ice dams can cause dangerous icicles, and cause damage to the house.
When warm air enters the attic, the heat causes snow on the shingles to melt. That water freezes when it gets to the edge of the roof and cools off. So your first line of defense is increasing ventilation and insulation.
You can help reduce ice dam problems by sealing the access panel. An uninsulated panel that is not weather-stripped will use a whopping 5% of your heat bill. Replacing the attic hatch is easy, and not too pricy. Click HERE to see what I found a Menards recently.
A lot of folks recognize the importance of insulation, but fail to address the issues caused by improper ventilation. When warm air gets into the attic, it is imperative that it leaves right away.
Most attics could use more insulation, and about half of the ones I inspect have uneven insulation, which reduces the overall effectiveness a lot.
The type of insulation is important, too. Fiberglass batts are easy to install, but do the worse job. Spray foam works great, but hold onto your wallet. For my money, I see great value in loose fiberglass or cellulose. You can learn more by clicking HERE.
Sometimes those actions aren’t enough, so removing the snow at the edge of the roof is your best option. If you use heat cables, don’t use a snow rake.