Tuesday, December 28, 2010

Ice Dams


Following a week of virtually non-stop food and festivity, I spent a good part of the day yesterday on a ladder chipping ice off the eaves to stop the flow of water into the house. There's something meditative about following the cleavages in the ice with a hammer and screwdriver, watching the chunks fly off through your yellow-tinted goggles, seeing how close you can get to the shingles without punching a hole in them. The little tap-tap-tap rings out through the neighborhood, while the incessant drip-drip-drip continues inside.

The ice itself has the look of white obsidian, wavy, smooth, and sheer. The task is seemingly endless, but it’s a thrill when you do hit an area where a puddle has collected; the ice is suddenly wet, it starts to come off easier, your deerskin choppers soon become soaked. Time to come in for another cup of coffee...

So much for global warming? Not really. It’s well documented that the earth’s frozen areas are in retreat, but there are exceptions. The seasonal snow cover has, in the past two decades, actually expanded across the high latitudes of the Northern Hemisphere, especially just north of the Himalayas, the Tien Shan, and the Altai in Central Asia. This pile of snow influences the atmosphere profoundly because it creates a large dome of cold air which the jet stream must bend around. A bigger pile of cold air generates a bigger bend. In response, the jet stream diverges more often, and more wildly, from its generally west to east path and begins to meander north and south, sending more warm air north from the tropics into Alaska and Greenland, and pushing cold air south from the Arctic on the east side of the Rockies across the interior of North America. Cold Siberian air, meanwhile, spills south into East Asia and southwestward toward Europe.

More snow, more ice dams. I’ve got the bamboo roof-rake out. There’s something poetic about scraping snow with bamboo, I guess. Yet the effort is half-hearted. It’s supposed to rain in a day or two…

4 comments:

Trout Caviar said...

John: Unless you really do enjoy the meditative, poetic aspects of ice dam removal and prevention, I'd highly recommend getting a winterization person in to look at your house. We used to have bad ice dams, but after we hired a brave fellow to slither around in our crawl space sealing up the heat bypasses, no problem. Happy New Year~ Brett

Allyson Ripple said...

Hi, John! Is that picture the actual snow on your roof? If it is, I hope your roof could still protect you from strong weather. Snow raking isn't the only solution; have your attic properly insulated. Ice dam is number one roof enemy, and if you experience it a lot, you better maintain your roof's health by having a professional check-up every few years.

Allyson Ripple @ DnMRoofing.net

Terence Watthens said...

John, ice dams can be prevented if the attic is properly insulated. Ice dams occurs when the heat of your attic melts the snow on the roof's surface, then the temperature outside freezes it and forms it into a solid ice. Keep your attic temperature low and keep it cold as the outdoor air.
Terence Watthens @ TheFidusGroup.com

Todd Bischoff said...

Careful with how you rake the roof. You might damage the surface of your roofing material if you hit so hard, making your ice dam problems worse. Have your roof insulated so that the ice dams won’t accumulate this much. Todd @ ABImprovements.com