How to Prevent Ice Dams

It's going to snow tomorrow. Lots of snow is going to pile up on roofs all over New Hampshire, and

at the bottoms of a lot of those roofs, ice dams are going to form. And every single one of those ice dams could have been prevented. Here's how:

The cause of ice dams is heat from indoors leaking out and causing some of the snow that's on the roof to melt. This melted snow runs down the roof until it hits the eaves (the overhang, where suddenly there's no heat escaping and everything's cold again) and quickly refreezes. The process continues until there's so much ice built up on top of the eaves that it keeps snow from sliding off. And that's not the worst part. As the ice dam grows, it can creep under shingles. Then when it eventually melts, it can leak into your house, causing water damage.

The best way to prevent ice dams in the long run? Make sure your roof is properly ventilated and your attic is properly insulated.

The best thing to do now to prevent ice dams in tomorrow's storm? If your roof is prone to getting ice dams, rake the eaves off periodically to prevent buildup. If buildup occurs, fill a nylon stocking with magnesium chloride ice melt. (Make sure it's magnesium chloride so you don't damage your roofing materials.) Toss the stocking onto the edge of your roof where the ice is forming and let it melt it off.

Tomorrow's expected to be windy, though, so with any luck, your roof will stay clear.

How to Choose the Best Ice Melt and Traction Products

There's no one best ice melt or traction product that's best for every home and every use. What you should get depends on a lot of factors, including what you need to accomplish, your building

materials, and even the lay of your landscaping. Here's the breakdown:

Salts:

Not all salts are the same, and it's important to read labels when buying them. Generally speaking, your choices will be sodium chloride (table salt), calcium chloride and magnesium chloride. The great advantage to salt is that it lowers the freezing point of water. In other words, it melts ice. The downside is that salt is corrosive. The different types of salt are corrosive to different materials, so make sure the salt you buy is approved for the material you plan to put it on. And unless you have someplace for the melted ice to go, you could end up with a pool of sub-freezing salt-water or slush, which can be at least as dangerous as ice.



Sand:

The great thing about sand is it doesn't wash away as easily as salt because it doesn't dissolve in water. It provides excellent traction and you don't have to worry about anyone slipping into a puddle and getting their foot soaked in negative-fifteen-degree water. It's also completely natural and noncorrosive. The downside is it doesn't dissolve, so it can clog up storm drains.


Roofs:

Looking for ice melt for your roof? Get calcium chloride. More about that next time in our post about ice dams.