The Science of Snow Load: How Much Weight Can Your Roof Really Handle?
When winter storms roll across Maine, the beauty of fresh snow often hides a silent stress pressing down on your home — snow load. Every roof, from coastal Cape homes to commercial metal structures, has a limit. Once that limit is exceeded, structural damage can happen fast — and dangerously.
So how much snow is too much? Let’s dig into the science behind snow load and what it means for your roof’s safety and lifespan.
Understanding Snow Load Basics
“Snow load” is the weight of accumulated snow and ice sitting on your roof. This weight depends on more than just how deep the snow is — it’s influenced by snow type, temperature, moisture content, and roof design.
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Light, fluffy snow: Around 5–7 pounds per cubic foot
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Wet, heavy snow: Can exceed 20 pounds per cubic foot
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Ice: Roughly 57 pounds per cubic foot
That means 12 inches of heavy, wet snow could weigh as much as four feet of powdery snow. It’s not the depth — it’s the density that matters most.
What Maine Building Codes Require
Maine’s building codes are no joke when it comes to snow load. Depending on where you live, your roof may be required to support anywhere from 50 to 90 pounds per square foot (psf).
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Southern Maine (York, Cumberland, Androscoggin): 50–60 psf
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Central Maine (Kennebec, Somerset): 60–70 psf
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Northern & Mountain Regions: 80–90 psf
Older homes built before modern codes may fall far short of these standards — a major reason why many roof collapses occur in aging or unreinforced structures.
Warning Signs of Overloaded Roofs
Snow-load stress rarely happens all at once. You can often spot the early warning signs before a disaster strikes:
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Sagging ceilings or visible bowing in rafters
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New interior cracks in drywall or plaster
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Creaking or popping sounds
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Doors or windows suddenly sticking
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Ice dams forming along eaves or gutters
If you notice any of these signs — act fast. The next snowstorm could push your roof past its breaking point.
Why Roof Shape and Pitch Matter
Not all roofs share the load equally. The steeper your roof, the easier it sheds snow. Flat or low-slope roofs, especially on commercial buildings, are far more susceptible to buildup.
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Steep-slope metal roofs: Naturally self-clearing
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Asphalt shingle roofs: Moderate shedding, moderate risk
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Flat EPDM or rubber roofs: Require regular removal and drainage checks
Professional roofing design accounts for how snow drifts, settles, and melts — because uneven weight distribution is what causes the most damage.
How to Safely Manage Snow Load
Homeowners often ask, “Should I remove the snow myself?” The short answer: only if it’s safe and only from the ground.
Here’s what we recommend at A Plus Roofing:
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Use a roof rake from ground level for light snow removal.
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Never climb on your roof in winter. It’s slippery, unpredictable, and dangerous.
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Call a professional for deep or heavy accumulation — especially if you see sagging or hear creaking.
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Maintain attic ventilation to minimize melting and refreezing, which adds ice weight.
Prevention Is Better Than Panic
A roof designed and maintained for Maine winters can carry its load — literally. But even a well-built roof weakens over time without upkeep. That’s why regular inspections matter most before the first major snowfall.
At A Plus Roofing, our seasonal maintenance program helps property owners prevent structural stress by checking:
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Roof framing and decking integrity
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Proper insulation and airflow
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Ice dam prevention systems
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Drainage and gutter clearance
Protect Your Investment Before Winter Hits
Snow load is more than just physics — it’s peace of mind. Knowing your roof can handle what Maine throws at it means fewer emergencies, lower repair costs, and longer roof life.
Don’t wait for the next storm warning. Schedule your Winter Roof Readiness Inspection today with A Plus Roofing. We’ll make sure your roof isn’t just built for Maine — it’s built for whatever Maine brings next.