Snow can be beautiful when it falls, but it can also be a burden on your roof if it’s a heavy snowfall.
There are lots of factors to take into account when considering when and how to remove rooftop snow. Read below to get all the information you need to craft your own plan of action.
Should I remove snow off my roof?
Before trying to figure out how to get the snow off your roof, you should determine whether you even need do it in the first place.
Most roofs are made to hold up to 20 lbs. per square foot of snow. A good rule of thumb is that if you have less than 12 inches of snow on your roof, you generally shouldn’t need to worry about removing it. But check your local building codes to verify the exact number for you.
Another determining factor is the pitch of your roof. Snow falls more easily off of steeper roofs, as gravity has more of an opportunity to help. But snow accumulates more easily on lower-pitch roofs, thus necessitating removal more often. Another good rule of thumb is that if 18 inches or more has fallen on a flat roof or a flat-pitch roof, it should be removed.
What kind of snow is a threat to my roof?
A snowfall’s level of threat to your roof depends much more on the weight of snow than it does the amount of snow. The heavier the snow, the greater the snow load.
And the wetter the snow, the heavier the snow. 12 inches of dry snow tends to weigh only 3-5 lbs. per square foot, while 12 inches of wet snow tends to weigh more than 20 lbs. per square foot.
Ice poses the greatest threat to your roof’s health, as it weighs nearly 60 lbs. per square foot.
Is it safe to remove snow from my roof?
A number of safety hazards need to be taken into account when determining the risks associated with removing snow from your roof. You should take the utmost caution and in many cases call in a professional.
A number of DIY snow-removal tactics are outlined below. But a good rule of thumb is that if you end up needing to go up onto your roof, that’s when you should hire a professional. It’s worth noting that more people die every year from falling off their roofs than from roof collapse.
Another risk to consider is power lines. If your home (and thus your roof) is in the vicinity of power lines, take extra care not to make contact with them. In these cases too, we advise the help of a professional for your safety.
When should I clear the snow off my roof?
In general, it’s better to be safe than sorry. If more than 12-18 inches have fallen—especially if the snow is wet or your roof pitch is less than 5 inches of rise—you’ll want to clear it.
Your home can also show other signs that snow removal is absolutely necessary to avoid structural damage. Here are a few:
- Cracks in the ceiling or drywall —> This shows the house is suffering under the weight of the snow.
- Popping or cracking noises in the ceiling —> This requires immediate inspection (and potentially evacuation).
- Sagging and/or water spots in the ceiling
- Roof leaks and water accumulation in abnormal areas —> This may be evidence of cracks in the roof under the weight of the snow.
- Doors rubbing against their frames and/or being hard to open —> This may show a displacement owing to downward pressure from the roof.
What is an ice dam?
Ice dams are one of the most costly causes of roof damage and repair for homeowners. They occur when snow on the roof melts, trickles down to the edge of the roof and/or gutters, and then refreezes.
This newly frozen ice buildup causes a “dam” that prevents snowmelt from exiting the roof and instead causes it to get underneath the shingles and wreak havoc on your house.
What causes an ice dam?
- Air leaks in the attic —> If warm air is leaking into your attic rather than flowing to the rest of the house, it will cause the snow to melt then refreeze. You may need to call an inspector who can determine where the air leak is occurring.
- Not enough insulation or ventilation in the attic —> Both insulation and ventilation prevent the warm air from filling the attic and thereby melting the snow.
- Cluttered gutters —> If your gutters aren’t clean, snowmelt will get trapped in them and refreeze. This risks damage to both your roof and your gutters.
To prevent ice dams from forming, make sure your home is clear of all three of these causes.
How do I fix an ice dam?
Grab some socks or pantyhose and fill them with rock salt or a more non-corrosive product made from calcium chloride. Then throw them up onto the edges of your roof where the ice has formed.
This will help the ice melt and create channels for snowmelt to flow off of the edge of your roof, into your gutters and through the downspouts onto the ground.
How do I remove snow from my roof?
There are a variety of methods and roof snow removal tools.
Snow rake (also known as a roof rake)
A snow rake might be the most popular way to clear snow from your roof. Here are the steps:
- Take a snow blower and clear a path around your house for the snow to fall from the roof.
- Grab your rake and adjust the poles to the proper length. You may need extension poles depending on the size of your roof. Make sure to avoid power lines.
- Drag the rake downward towards you and knock the snow build up onto the ground.
*When using a snow rake, take extra care not to damage your shingles. Leave about an inch of snow on your roof to ensure that you’re not raking your shingles.
Heated cables
Before the next snowstorm hits, you can buy electric cables from your local hardware store or online and install them across your roof. When it snows, just turn them on to heat up the snow and cause it to melt rather than accumulate on your roof.
Rope
Grab a rope and another person. Throw one end of the rope over to the other side the roof (you may need to tie a weight onto it to do so). Each person grabs an end of the rope and alternates pulling in a sawing motion. This can dislodge the snow and cause it to fall off the roof in chunks.