If you live in a climate that gets snow and freezing temperatures, you might already know about the damage that ice can do to your roof. It is a good idea to know how ice dams are formed, the damage they cause, and how to deal with them.
How Ice Dams Form
When snow collects on your roof, escaped heat from inside your home gets into your attic and melts the snow. This melted snow runs down the warm roof, then freezes when it reaches the cold roof overhang. After several days of this melting and freezing, a thick layer of ice builds up on your shingles. This ice can get under the shingles, then melt and run into your attic and into your home.
Ice Dam Repair and Removal
An ice dam on your roof can lead to a water leak in your home. To help stop this leaking water until you can repair the problem, use a box fan.
Switch a box fan on inside your attic, aimed at the leaking spot of your roof. The cool air will prevent the home's heat from thawing the ice. The fan will cause the water to freeze on the underside of your roof, temporarily stopping the leak.
Once you have stopped the water from leaking, calcium chloride and an old nylon stocking will help you next:
- Fill an entire leg of a nylon stocking with calcium chloride.
- Lay the stocking on your roof, vertically over the ice dam.
- The calcium chloride will melt a channel in the ice on your roof and keep new ice from forming.
- Any new melting snow will run off the roof, down the calcium chloride-melted channel.
Bad Ice Dam Removal Techniques
Don't use an axe or ice pick because they can both cause damage to your shingles. Also, don't use a blowtorch, or a power sprayer. The blowtorch can catch your home on fire, and the power spray can permanently damage your shingles.
Rock salt is also a bad idea to use on your shingles because rock salt contains sodium chloride which corrodes metal. The metal nails in your roof will corrode and your shingles will become stained from the sodium chloride.
Ice Dam Prevention
A temporary prevention for ice dams is to use a roof rake to scrape the snow from your home's roof after each snow fall. Make sure to only use a roof rake that has a long enough handle so you can scrape snow safely from the ground. This prevents the snow from melting, then freezing into an ice dam, but it does not address the problem causing the ice dams.
Installing a waterproof lining under your home's shingles can help keep ice from melting and seeping into your home through your roof. This will help to prevent water leaks from ice dams, but does not eliminating the cause of the ice build-up: heat escaping from your home.
The best way to deal with ice dams is to prevent them from occurring in the first place. The reason that ice dams form on your roof is because your home is leaking heat into your attic space, causing snow to melt, then turning to ice as it freezes later on. If you plug any holes in your home that leak heat into your attic, you will also benefit by having a more energy efficient home.
One easy way to find out if any spaces in your home are leaking heat into your attic is to go outside and look at your home's roof after a snow storm. You will be able to see patches on your roof where the snow has already melted. You may have to wait a couple of days after the snow storm to give your home time to leak heat to melt the snow.
You can also get into your home's attic space and look for gaps in the insulation or feel for warm spots. Once you know the areas of your roof that are being inadvertently heated, seal up these spaces in your attic.
Patch any spaces along the attic floor that are missing insulation. Inspect any vents that are directing home air to the outside. Make sure they vent air to the outside, not into your attic space. Also make sure the vent goes through the wall or ceiling, but not through a soffit in your home.
By being aware of the causes of ice dams, knowing how to do roof repairs for them, and keeping them from happening again, your home will be more energy efficient and ice dam-free.