Snow On Your Roof
Snow can be quite deceiving when it comes to weight. The type of snow and the amount of water saturation varies dramatically. As a general rule you can estimate that one cubic foot of snow will weigh about 19 to 20 pounds. Or in Canada a 30 cm x 30 cm x 30 cm cube is about 9 kg.
That being said , if you have an area that is 10 ft x 10 ft x 1 ft thick that would be about the same as the average compact car sitting on your roof. It is always a good idea to watch for excessive snow and uneven snow loads on your roof. If you have metal roofing you also need to be mindful of where that snow build up will slide off. Snow breaks on roofs can help prevent the snow from sliding off on to driveways and walkways but they are only effective to a point. Having a ton or more snow suddenly landing on your car can cause a lot of damage. Or worse if it was to slide off and hit a person.
There are a variety of products on the market to help folks remove snow safely from the ground. If your roof is too high it is a good idea to have these areas checked regularly, when conditions allow, to ensure there is no damage caused by the snow or ice damming.
Ice damming is usually a sign of other issues with venting requirements under the roof. Having your roof inspected regularly is a great way to prevent costly repairs due to moisture intrusion later on.
Another issue with ice damming and snow buildup is your eves. Buildups can overload your eves and cause them to pull away from the home. This will allow moisture to penetrate your fascia and cause rot.