Is Your Ice Dam Vertical or Horizontal? Big Factor in Ice Dam Removal Costs

The size of your home isn’t always a good indicator of how long it will take to remove an ice dam on your roof, and it won’t help you estimate how much ice dam removal will cost.  That’s because the orientation of the ice dam is a huge variable.

As you might expect, larger homes tend to take longer, because they have more linear feet of roof overhang.  But just because you have a smaller house does not necessarily mean your ice dam removal will go faster.  Often it’s just the opposite.  Cozier homes can accumulate huge amounts of vertical ice: ice that stretches up your roof, rather than laterally along the overhang.  An ice dam with substantial vertical growth on a smaller home can take just as long – sometimes longer – to remove than a more-horizontal ice dam on a larger home.

Partly that’s because the attics of smaller homes get HOT.  Smaller attics build up heat more quickly and easily than larger attics can.  That means smaller roofs’ decks and shingles get especially hot, causing snow to melt rapidly.  That melting often causes a thick layer of ice to quickly build and crawl up the roof, nearly to the ridge in some cases.

Because water flows downward, the ice is much thicker on and near the overhangs.  A larger house can have more linear feet of ice dams because its roof has more linear feet of overhang.  But smaller roofs can have more “square feet” of ice dams.  Much of that square footage is high up, harder to reach, and must be removed in a slower, more delicate fashion.  Blasting off an ice dam that’s 2 feet thick goes much faster pound for pound than gently removing 2 inches of ice frozen hard to your shingles.  “Square feet” of ice will always take longer to remove than “linear feet” of ice.

Your home may be comfortable in size, but don’t get too comfortable with the idea of a quick ice dam removal job.