Wondering how much snow your roof can handle with each added snowfall? It’s a very common question, especially for Canadians. The accumulated weight of heavy snow, moisture, and ice can create dangerous and expensive circ*mstances for homeowners. To learn more about how to protect your roof from the snowy winter season, read on.
Contents
- 1 How Much Weight Can a Roof Handle?
- 2 Monitor Your Roof
- 3 Removing Snow from the Roof
- 4 Wear Boots with Excellent Grip
- 5 Use a Plastic Shovel with a Long Handle
- 6 Avoid Chipping Ice
- 7 Take Your Time
How Much Weight Can a Roof Handle?
Snow and ice can lead to a dangerous roof collapse, even for newer roofs. That’s why it’s imperative to be aware of the weight your roof can support, and when it should be cleared. Roofs that are most at risk are flat roofs and low-pitched designs because they allow snow to accumulate continuously with nowhere for it to fall off. The majority of roofs are designed to withstand approximately 20-40 lbs per square foot. This can change depending on the type of snow. For example, snow that’s packed with moisture will be much more dense and heavier than light and fluffy snow.
Monitor Your Roof
One of the best ways to prevent a roof collapse is to monitor your roof during the winter months. Keep an eye on icy edges and icicles that form, as well as ice dams. If there have been back-to-back days of consistent snowfall combined with moisture, you may need to remove some of the snow.
Removing Snow from the Roof
Removing snow from your roof can be a dangerous job. It can end up damaging your roof and causing injury to you. We recommend consulting with a roofing contractor beforehand.
If you’re doing it yourself, here’s what to keep in mind:
Wear Boots with Excellent Grip
Before you begin, make sure you’re wearing the right attire to stay safe. In particular, wear good boots with very good traction.
Use a Plastic Shovel with a Long Handle
A metal shovel can end up scraping and damaging the roof shingles. Use a plastic one with a long handle instead so you can easily scoop and remove the snow.
Avoid Chipping Ice
If the snow has hardened along the edge, or if there’s ice, avoid chipping it with the shovel. Keep the shovel along the surface layer to avoid causing damage and focus on removing as much as you can without adding too much pressure.
Take Your Time
When it comes to removing snow from the roof, it can take some time. So don’t plan to have it don’t in a flash right before you head out or have something pressing to do. Give yourself at least an hour.
If you need repairs after the winter season in Ottawa, give us a call at Roofmaster!
FAQs
Roofs that are most at risk are flat roofs and low-pitched designs because they allow snow to accumulate continuously with nowhere for it to fall off. The majority of roofs are designed to withstand approximately 20-40 lbs per square foot. This can change depending on the type of snow.
How much snow can a roof hold in Ontario? ›
According to the National Research Council of Canada Open in a new window , the minimum snow load amount that a roof should be able to handle is 21 pounds per square foot (22 pounds if you live in Alberta). That's about 2 to 2.5 feet of packed snow!
How much weight can my roof hold of snow? ›
Estimate how much weight your roof can support
House roofs should support 20 lbs./square foot of snow before they become stressed. Local building codes dictate the snow load required for residential roofs. Contact your local building code department to determine the snow load requirements for your area.
What is the average snow load on a roof? ›
According to the University of Wisconsin Cooperative Extension Service, those approximate ranges are: Light snow: five to 20 pounds/square foot. Packed snow: 20 to 40 pounds/square foot. Packed snow and ice: 40 to 58 pounds/square foot.
Will my roof collapse under snow? ›
However, what some people don't know is that snowfall can become so heavy that it exceeds the carrying capacity of the roof, leading to structural damage. Over time, this damage can cause the roof to become unstable and cave in.
How much snow can a roof hold in Canada? ›
DETERMINING HOW MUCH WEIGHT A ROOF CAN HOLD
According to the National Research Council of Canada, the minimum snow load a roof is required to handle is 21 pounds per square foot (or 1 kilo Pascal). Alberta's building codes require a minimum of 22 pounds per square foot (or 1.06 kolo Pascals).
How steep of a roof for snow to slide off? ›
On roof slopes approaching 45 degrees (12/12) snow is very likely to slide and snow guards should be considered in areas where it is necessary to control snow slides. On steeper roofs, snow fences instead of snow guards, or a combination of both, may be necessary to achieve the snow retention desired.
Can a roof hold a 400 pound person? ›
Residential roofs can hold a minimum of around 20 pounds per square foot then top out at 100 pounds per square foot.
How do you know if there is too much snow on your roof? ›
If you notice any of the following warning signs, evacuate your home immediately and call 911 because your roof may be in danger of collapsing.
- Sagging ceiling.
- Major water leaks.
- Cracks in walls.
- Loud cracking noises.
If it snows 12” of light and fluffy snow, it will weigh about 5.2 pounds. Unsurprisingly, wet snow is the heavy stuff. If it snows 5” of wet snow, it will weigh about 12.5 pounds.
The design roof snow load for residential buildings in MN is set by state statutes and is 42 pounds per square foot (psf) in northern MN and 35 psf in southern MN.
What is the best roof for heavy snow load? ›
Slate roofing has been popular for a very long time due to its durability and appearance. It does well in extreme temperatures, making it one of the best roofing materials for cold climates. It is also strong enough to withstand wind, storms, hail, and even fire.
What does 20 lb snow load mean? ›
Thus, a roof designed to a carry a snow load of 20 lbs.. per horizontal square foot is expected to support nearly 12 inches of wet, heavy snow. ( University of Arkansas Division of Agriculture)
What is the snow load for Ontario? ›
The Ontario Building Code | Specified Snow Load
| Item | Column 1 | Column 2 |
|---|
| 1. | Low | 0.8 |
| 2. | Normal | 1 |
| 3. | High | 1.15 |
| 4. | Post-disaster | 1.25 |
2 more rowsRoofs in snowy climates should have a slope of at least a 10-degree pitch minimum. A steeper angled roof sheds the snow more quickly. While the angle of the roof helps shed snow, adding too many angles to the roof for a more aesthetic effect could cause structural problems with snow shedding in the wintertime.
Is it OK to have snow on your roof? ›
Believe it or not, snow on your roof isn't always a bad thing. In fact, there are some advantages to having a light layer of snow on top of your home, including: When snowflakes gather on top of each other, air pockets form, causing sound to become muffled.
What happens if you leave snow on your roof? ›
While the weight of the snow is the top factor to consider, water damage is also quite common. Temperatures above normal can melt the accumulated snow and cause leaks. Once the temperatures drop again, these leaks can then refreeze, pulling up the shingles and seriously damaging the roof.
