Damn These Ice Dams!

It's been a crazy winter this year. Weekly snow storms, endless shoveling and collapsing roofs all over the news making everyone worry. As I understand it, the weight of the snow is not an issue for the typical pitched roof home.

There is a potential problem on the roof however... ice dams. All those icicles hanging from the edge of the roof are pretty but they're also a bad sign. What they indicate is that ice is forming at the edges of your roof. This ice forms because the temperature at the edge of the roof is colder than the rest of the roof. This may mean that you need more insulation in your attic to keep heat from rising up and creating this temperature variance. Ideally your attic is close to the outside temperature. Although I've been hearing that this year the conditions have been extreme enough that even homes with very well insulated attics are not immune to this problem.

So, what happens when you get a build up of ice along the edge of your roof? The snow on the warmer part of the roof melts and moves down toward the edge of the roof but, is stopped by the wall of ice. Some of the melted snow will freeze into the ice dam but some will remain as water. Now, you've got a collection of water trapped on your roof. They do put a barrier under the shingles that goes up 4' from the edge. Because of the huge amount of snow we've had and the cold temperatures the water in many cases is rising up past that 4' mark. Once that happens you'll start to see leaks, often in the form of water running down your walls. Not good. This is why a lot of people are hiring companies to go up and clear off the roof.

I did not do this and I do not plan to mainly because it's expensive. I'm hearing most people say they're spending about $1000 to have it done. Also, I really thought I was fine. Up until this past weekend there had been no problem at my house. Then, on Saturday morning I noticed a strange looking spot on the living room curtain. It was a wet spot. I opened the curtain to find water dripping down the window. It was pretty minor but, still, not good.

I immediately did what all Internet savvy people do. I got online and Googled ice dams. I found some great information and was able to take care of the problem myself. I have the advantage of living in a one story house which makes this problem a little easier to address. If you are dealing with a higher roof you may want to make the investment and call in professional help for this.

On the This Old House web site I learned about something called a melt sock that you can make yourself. You take a pair of pantyhose and cut off the legs. You then fill the legs with ice melt. They recommended calcium chloride. I  had some magnesium chloride which also works. When I went to make my first melt sock the nylon began to run. In order to keep ice melt from spilling all over the place I ended up making a double layer sock by putting one leg inside the other. This worked quite well. Once you fill the sock with ice melt, tie off the end. Then, place the melt sock up on the roof, perpendicular to the roof line. As the ice melt in the sock melts the snow and ice on the roof it creates a channel that lets the water run off the roof.

That all sounds great doesn't it? The problem was that I had water coming into my living room and I did not want to wait for this thing to melt through the foot and a half thick ice dam. I found this diagram of an ice dam helpful in that it gave me a clearer idea of exactly what I was dealing with and how to attack the problem. It would have required a lot of shoveling to get a ladder out there (the problem was in the back of the house). Instead I was able to create a sort of platform by packing down the snow. This got me up about 2' and close enough to the height of the roof that I was able to get to work.

First, I used a push broom to remove some of the snow above the spot where I was going to work on the ice dam. You can also use a special tool called a roof rake. The broom worked fine. Then I started hammering away, at the ice dam, literally. I had a hammer and used a screwdriver as a chisel and started breaking off pieces of ice and weakening the ice dam by creating cracks. After a while I decided the progress was too slow. I went out to the shed and got a heavy metal shovel and started beating on the ice dam. I'm sure it was quite a sight. I basically pointed the edge of the shovel at the ice dam and drove the shovel at it. The advantage of using a shovel over something like an axe was that it allowed me to hit the ice dam with the force going parallel to the roof rather than perpendicular. This meant that I could hit the ice dam as hard as I wanted without risk of damaging the roof.

After working at it with the shovel for probably half an hour or so I started to get a steady stream of water running off the roof. Now that I had a decent escape channel started, I put the melt sock in it to keep the process going. When I went back inside I could see that the dripping in the living room window had stopped. The warm temps the last few days have helped a lot but, I'm hopeful that the work I did will be enough for the winter. Also, I'm planning to keep a melt sock up there for maintenance. I find that after a couple of days the ice melt has completely dissolved and the sock needs to be replaced. I'm alternating two melt socks. When one is empty I bring it in to dry and I fill up the second sock and put it out.

I hope that you are fortunate enough to not have to deal with this problem. Though if you've read this far that's probably not the case. I hope this helps.