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Q: My roof is old and I am worried about the snow load on my roof. How much does snow weigh and how do I know if my roof can handle the weight?
A: Some of the smallest snowflakes are no larger than the diameter of a human hair. It’s hard to believe that something so small can weigh so much!
However, it’s true—snow is heavy and snow load on your roof can absolutely cause damage. Here’s what you need to know.
Can my Roof Handle Heavy Snow?
Even if math isn’t your strong point, we can give you a general idea if your roof can handle a snowstorm or otherwise significant snowfall.
According to the Insurance Institute for Business and Home Safety, most residential roofs are able to withstand a reasonably heavy snow load before becoming stressed. Once the snow load accumulates to 20-25 pounds per square foot, this becomes the danger zone.
Generally, this means that most roofs can safely support up to 2 feet of light, fluffy snow—especially snow with a water-to-snow ratio of 10 to 1—before any cause for concern. However, as snow becomes wetter and heavier, or if additional accumulation occurs without melting, the risk to your roof increases significantly.
When your roof becomes stressed due to the weight of snow, you might begin to notice:
- Noticeable bends or cracks in the attic.
- Damaged or splintering rafter beams.
- New cracks in drywall or plaster around door frames.
- Doors are suddenly sticking when they used to open with ease.
- Cracks and leaks in the ceiling.
- Sections of your roof are sagging.
The good news is that roof collapse typically doesn’t happen all at once. It’s a process of breaking down until your roof can no longer handle the weight.
However, if you suspect that your roof cannot handle significant snowfall, it’s important that you contact a roofing contractor in MA. A roofing contractor can help evaluate whether your roof is subject to collapse due to snowfall.
How Much Does Snow Weigh?
The weight of snow depends on the type of snow in question. To calculate the weight of snow, you take 7.48 gallons per cubic foot of water, which is about 62.4 pounds. You then divide it by the amount of snow (in inches).
But here’s where it gets interesting: not all snow is created equal. The weight of snow can vary dramatically depending on how much water is in it—what meteorologists call the “snow to water ratio.”
- Light and fluffy snow has a high snow-to-water ratio, typically around 15 to 1 (meaning 15 inches of snow equals 1 inch of water). Sometimes, especially with very cold storms, it can be as much as 30 to 1! In these cases, 12” of light and fluffy snow weights about 5.2 pounds.
- Heavy, wet snow is on the opposite end of the spectrum, with a ratio as low as 5 to 1 (5 inches of snow equals 1 inch of water). That means it’s far denser—and heavier. For example, just 5” of wet snow can weigh about 12.5 pounds.
So, whether you’re dealing with powdery snowflakes or the heavy, slushy stuff, the snow load on your roof can add up quickly. Knowing which type of snow has landed can give you a better idea of how much weight your roof is really supporting.
With this information, you’re now likely wondering about the weight of snow load on your roof. There is a calculation for this, too!
Putting It Into Perspective: The Weight of Snow vs. Pickup Trucks
To give you an idea of just how much weight your roof might be carrying, let’s use something we can all picture—a pickup truck.
- Light, fluffy snow: If your roof accumulates one foot of the powdery stuff, that’s roughly equivalent to parking a single pickup truck on top of your house. Not something you see every day!
- Heavy, wet snow: Now, imagine that same foot of wet, dense snow. Suddenly, you’re nearly tripling the load—think three pickup trucks, all lined up on the roof.
Stacking up more snow only multiplies the problem:
- Two feet of light snow? Picture two pickup trucks overhead.
- Two feet of wet snow? It’s essentially the weight of about six pickup trucks pressing down.
This comparison really highlights why it’s so important to keep an eye on snow accumulation as winter goes on. Even if the snow looks innocent, your roof could be holding a fleet of Fords without you even realizing it!
How to Calculate Snow Load on Roof
Calculating snow load on your roof depends on two factors: whether it’s a flat roof or a pitched roof. The snow load will be different depending on the construction of your roof.
Measuring Snow Load for Flat Roofs
Even though we typically measure snowfall in inches or feet, you’ll want to think of it in terms of feet. The easiest way to measure snowfall on a flat roof is to take a yardstick and measure what looks like the average overall snowfall. If there is 18 inches of snow this is expressed as 1.5 feet.
You’ll then take the depth of snow in feet and multiply it by the weight of 1 cubic foot of snow. This is 6 to 8 pounds for fluffy snow and 20 pounds for wet snow. The same volume of ice can weigh 3 times the amount.
To put things into perspective, let’s say you double the snowfall to 2 feet. For fluffy snow, that’s about the weight of two pickup trucks spread across your roof. For wet, heavy snow, it can be as much as six pickup trucks sitting on top of your house. That’s a lot of weight for any roof to handle!
After you arrive at your answer, multiply it by the square footage of your home. This is how much snow load or pounds of pressure from snow is on your roof.
Measuring Snow Load for Pitched Roof
With a pitched roof, you’ll need to know how much snowfall is expected and determine the pitch of your roof. You’ll need to measure the rise and the run and divide the answer by the run, then convert it to a fraction ratio of 12.
From here, it’s best to use a snow load calculator such as this one from Cornell University.
With the weight of snow fresh in your mind, here’s how you can tell if your roof can handle the weight.
Source: https://courses.cit.cornell.edu/arch264/calculators/example2.3/index.html
Recent New England Winters: A Milder Trend
Is recent snowfall a cause for concern? Prior to the 2025-2026 winter season, snow hasn’t been much of an issue for New England roofs.
- Over the last 2–3 years, New England has experienced relatively mild winters compared to historical averages.
- Snowfall totals have been below average in many areas, with more frequent periods of rain, slush, or mixed precipitation.
- Much of the snow that did fall was the light, fluffy variety—visually impressive, but not especially heavy or damaging to rooftops.
- These lighter winters have generally reduced the stress on roofs, minimizing the risk of structural strain or ice dams.
- Warmer-than-average stretches during past winters allowed snow to melt quickly, preventing the long-term accumulation that typically causes roof issues.
This Winter’s Forecast: A Harsh Turn Ahead from Farmers’ Almanac
Will snowfall be a danger to your roof for the 2025-2026 season? There’s a possibility of running into snowload problems, according to Farmers’ Almanac:
- The Farmers’ Almanac warns New Englanders to prepare for one of the coldest, snowiest winters in years for the 2025–2026 season.
- Expect frequent snowstorms blanketing the region from late fall through early spring.
- The Atlantic Coast will see a mix of snow and rain, creating icy, unpredictable conditions.
- The forecast highlights dramatic temperature swings and widespread wintry weather that will test homes and infrastructure.
- Consistent cold snaps are expected across the Northeast, from Minnesota to Maine.
- A particularly intense cold spell is predicted for January, increasing the risk of frozen pipes and roof ice buildup.
- The Almanac’s warning: “Chill, snow, repeat”—a reminder that winter will be relentless and extreme.
Now is the time to inspect and prepare your roof—being proactive today can prevent costly damage when the weather hits hard.
Recent Roof Collapses from Heavy Snowfall
Heavy snowfall in New England has led to numerous structural failures over the past decade. Here are some of the most notable incidents:
1. Winter 2023 – Massachusetts & New Hampshire
February 2023: Several commercial and residential buildings in Massachusetts and southern New Hampshire experienced partial roof collapses after back-to-back Nor’easters dumped more than 24 inches of snow in some areas.
Cities affected: Worcester, MA and Nashua, NH reported emergency responses for structural damage.
2. Winter 2022 – Maine
January 2023: A warehouse roof collapsed in Lewiston, ME due to snow and ice buildup after a multi-day storm cycle.
No injuries were reported, but the incident prompted safety inspections across several counties.
3. Winter 2015 – Historic Season
February–March 2015: New England saw one of its snowiest winters on record. Thousands of reports of roof collapses (both minor and major) came from across Massachusetts, Connecticut, and Rhode Island.
Boston alone recorded 110+ roof collapse incidents in a single month.
4. Patterns & Warnings
Local governments and fire departments have increasingly urged homeowners and businesses to remove snow from roofs after 6 inches or more, especially during repeat storms.
Flat roofs, older structures, and poorly maintained gutters are consistently the most vulnerable.
Free Estimate: Book Your Roof Replacement Before the Spring Rush
If you are worried about the structure of your roof, it’s better to call Coastal Windows & Exteriors sooner than later. Spring appointments are already booking up and there’s still time to get ahead of the rush and take advantage of our winter promotion! Contact us to get started. – ( #Online booking link )