If you live in an area that sees several feet of snow every year during the cold winter months, then you know that this snow will pile up on your roof. In some cases, ice dams will build as well. Ice dams are formations of ice that build around roof valleys and edges. These dams will build for a variety of reasons, like when a nearby stove or fireplace chimney causes the snow to melt and then freeze as it collects on top of the roof. Ice dams often cause roof leaks as the ice closest to the roof melts and then forces its way through your shingles. While you may not be able to keep ice dams from forming due to your heating system or the pitch of your roof, you can deal with the formations by melting them as quickly as possible with the suggestions listed in this article.
Use Calcium Chloride
It is wise to remove most of the snow from your roof after a large snow storm to keep ice from forming underneath the snow. This also helps to reduce pressure if you are concerned about the snow collapsing your roof. However, it is not entirely safe to climb around on an icy roof for an extended period of time, especially if you are mostly concerned about ice dams. Instead of clearing off the whole roof, deal with the valleys of the roof that are most likely to build with ice.
You will first need to dig a channel where melting snow and ice can easily drain away from your roof. Use a shovel to dig a 6 to 12 inch wide path that runs from the valley to your roof gutter. Afterwards, purchase some calcium chloride snow and ice melting pellets from your local home store. Purchase two or three pairs of inexpensive stockings made for women as well. If possible, look for ones that are made with the most nylon. This will prevent holes or rips from forming in them.
Fill each leg of the stockings with a generous amount of calcium chloride, and cut the top of each stocking leg and place a secure knot on the top. Lay the filled stockings along the valley of the roof where the ice dam is located. The calcium chloride will slowly dissolve and eat away at the snow and ice in the area. Make sure to remove the empty stockings an hour or two after you secure them or they may get stuck to the roof in the freezing weather. Also, think about skipping the calcium chloride pellets and the stocking if you have a metal roof or if flashing is located near the roof valley. The pellets may cause a corrosion concern. Consider using liquid calcium chloride instead that is poured directly on the roof valley, since this will not cause corrosion.
Also, you can use the stocking method to add rock salt to the roof if snow is not piled on the ice dam area. However, do not use salt if snow is present to save yourself some money. Salt does not do a very good job of melting the snow. The calcium chloride does though, since it produces a great deal of heat as it dissolves.
Add Heat Cable
If ice typically forms on the edges of the roof instead of the valleys, then it is best to make sure that the water that runs down the length of your roof cannot become cold enough to completely freeze as it nears your gutters. You can prevent freezing by installing heat cable around the very edge of your roof. This cable is similar to the heat tape that is used to keep water pipes from freezing. The cables are low wattage electrical wires encased in a rubber casing that produce heat. The cables turn on and off automatically to reduce fire risks, and you can purchase kits to install them yourself.
If you do decide to add the cables to your roof on your own, place them in a zig-zag pattern along the edge of the roof to provide pathways for melted water to flow off the edge of the roof. Also, think about adding a small amount of the cable to the insides of your gutters if they typically fill with ice in the winter. This is wise, because an ice dam can build from the gutter up to the roof edge. You should make sure that you leave more than enough slack on the end of the cable too, so it can be easily plugged into an outside outlet or it can be secured to an outdoor extension cord that can be plugged into an indoor outlet. Clips are also needed to keep the cable in place, so secure a clip on the top and bottom of each zig-zag to keep the cable secured. If you aren't comfortable doing this yourself, consider reaching out to a roofing company for more information.