The safest way to remove snow from roof edges and lower slopes is from the ground, with a long-handled roof rake, taking small bites and leaving a thin layer of snow on the shingles. Never climb onto a snowy roof or work from a ladder in icy conditions. Most Minnesota roofs are built to carry a lot of snow, so you usually only need to rake after heavy storms, on vulnerable roofs, or to cut down on ice dams.
This guide covers when roof snow actually needs to come off, how to judge snow load, a step-by-step method for using a roof rake, and the situations where you should leave the job to a professional crew.
In this article
- Do You Need to Remove Snow From Your Roof?
- How Much Snow Is Too Much? Understanding Snow Load
- When to Remove Roof Snow
- Warning Signs Your Roof Is Overloaded
- Tools You Need
- How to Use a Roof Rake Safely: Step by Step
- Safety Rules for Roof Snow Removal
- Tips for Different Roof Types
- What About the Ice?
- When to Call a Professional
- Frequently Asked Questions
Do You Need to Remove Snow From Your Roof?
Often, no. Minnesota’s building code requires buildings to be designed for heavy snow. State rules set the design ground snow load at 50 pounds per square foot in most of the state, including Hennepin and the rest of the Twin Cities metro, and 60 pounds per square foot in a list of northern counties. Engineers use that ground figure to calculate how much snow a roof must carry.
That said, there are good reasons to clear some or all of the snow:
- Ice dams. Ice dams can’t form without snow on the roof. Raking the lower few feet cuts off the meltwater that feeds them.
- Older or altered roofs. A house built long before current codes, or one with past structural repairs or sagging, may not have the same capacity.
- Low-slope sections. Porch roofs, additions and flat roofs don’t shed snow, so it piles up.
- Drifts. Wind piles snow against walls, in valleys and on lower roofs below taller ones. A drift can weigh far more than the even layer elsewhere.
- Rain on snow. Snow soaks up rain like a sponge and gets much heavier without getting any deeper.
- Garages, sheds and carports. Accessory buildings are often built more lightly than the house.
How Much Snow Is Too Much? Understanding Snow Load
Depth alone doesn’t tell you how heavy the snow is. Weight depends on how much water is in it. The Insurance Institute for Business & Home Safety (IBHS) offers these rough equivalents:
| What’s on the roof | Roughly equals | Approximate weight |
|---|---|---|
| 10–12 inches of fresh snow | 1 inch of water | 5 lb per sq ft |
| 3–5 inches of old, packed snow | 1 inch of water | 5 lb per sq ft |
| 1 inch of ice | 1 foot of fresh snow | 5 lb per sq ft |
IBHS says a typical roof can handle about 20 pounds per square foot of snow before it becomes stressed, and older roofs or roofs with past problems may handle less. By its estimates, that’s around 4 feet of fresh snow, but only about 2 feet of old, packed snow. Two feet of old snow plus two feet of new could reach 60 pounds per square foot.
These are rules of thumb, not an engineering assessment. A roof built to current Minnesota code may be designed for more, and an older or damaged one for less. If you’re unsure about your home, a structural engineer or your city’s building department can help.
Snow on the ground vs. snow on the roof
Wind, sun and heat from the house all change how much snow stays on a roof. Use the ground as a starting point, then look at the roof itself, especially low spots, valleys and areas below taller roofs where drifts collect.
When to Remove Roof Snow
Good times to rake include:
- Soon after a heavy snowfall, while the snow is still light and fluffy. It’s far easier to move than snow that has settled and crusted.
- Before a forecast of rain or a warm-up, which adds weight and kicks off melting and refreezing at the eaves.
- When you see ice dam warning signs, such as thick ice at the roof edge, large icicles, or water stains on ceilings near exterior walls.
- When snow has built up over several storms on a low-slope or older roof without melting off.
The Center for Energy and Environment in Minneapolis notes that to work against ice dams, raking has to be done repeatedly and completely, after each significant snowfall, not once a season.
Stop and get help instead of raking if you see signs the roof is under stress (see below).
Warning Signs Your Roof Is Overloaded
IBHS lists warning signs that a roof is struggling under snow. The ones most relevant to homes include:
- Sagging sections of roof or ceiling
- Severe leaks
- Cracked or split wood framing visible in the attic
- Bends or ripples in supports
- New cracks in walls or masonry
- Interior doors that pop open or stick, and windows that suddenly become hard to open
- Creaking, cracking or popping sounds from the roof
If you notice any of these, IBHS advises getting everyone out of the building immediately and having it inspected. Don’t try to clear the snow yourself at that point, and don’t go into the attic to investigate.
Tools You Need
- A roof rake. A wide blade on a long, telescoping pole lets you reach the roof from the ground. Pick a length that reaches the area you need without stretching over your head at an awkward angle.
- A nonconductive pole if there are power lines anywhere nearby. IBHS warns that aluminum rakes conduct electricity. OSHA recommends extendable, nonconductive poles near power lines.
- Head and eye protection. IBHS recommends protective headgear and goggles, since snow and ice can slide off in chunks.
- Boots with good traction and warm, waterproof gloves.
- A shovel to clear the snow that lands on the ground.
- A helper. IBHS suggests having someone outside with you to watch for hazards.
How to Use a Roof Rake Safely: Step by Step
OSHA’s guidance on roof snow points to ground-based tools, like snow rakes, as the way to avoid the biggest danger: falls. Here’s how to do it.
1. Look up before you start
Find where the electrical service line connects to your house and any other overhead lines. Stay well away from those areas. OSHA tells workers to keep at least 10 feet from overhead power lines and to treat every line as energized. If you can’t rake a section while keeping that distance, leave it.
2. Plan where the snow will land
Raked snow falls right where you’re standing, sometimes all at once. Clear the landing area of people, pets and cars. Travelers recommends not piling snow on walkways or blocking exits, and don’t bury gas meters, furnace or water heater vents, or dryer vents.
3. Start at the edge and work up
Stand well back from the eave. Begin at the roof’s edge and pull down small amounts at a time, then reach farther up the slope with each pass. Taking big bites from high up can bring a heavy slab sliding down on you.
4. Pull with the slope, not across it
Draw the rake straight down the slope, in the same direction the shingles shed water. Dragging sideways or pushing up can catch shingle edges.
5. Leave a thin layer behind
Don’t scrape down to the shingles. IBHS recommends shaving the snow down to about 2 to 3 inches rather than clearing the roof bare, which can damage shingles and other roof coverings.
6. Clear enough to matter
To help with ice dams, Travelers suggests clearing roughly 3 to 4 feet up from the roof edge. If you’re reducing weight, work evenly across the roof. OSHA notes that removing snow unevenly can leave an unbalanced load.
7. Finish at ground level
Shovel the snow away from the foundation and clear the bottom of downspouts so meltwater has somewhere to go.
Safety Rules for Roof Snow Removal
- Never climb onto the roof. Snow hides skylights, slick spots and roof edges. OSHA identifies falls as the leading cause of death and injury in roof snow removal.
- Skip the ladder. IBHS warns that ice and snow build up on rungs and boot soles. Travelers also flags ladders in snowy, icy conditions as dangerous.
- Respect power lines. Keep your pole and yourself well clear, and use a nonconductive pole near any lines.
- No heat or flames. IBHS warns against heat guns, hair dryers and open flames on roof snow and ice. They can damage roofing and gutters and start fires.
- Stay out from under icicles and overhangs where snow can slide off.
- Pace yourself. Heavy snow is hard work in the cold. Take breaks, stay warm and stop if you feel strained or dizzy.
- Don’t work alone. Have someone nearby who can call for help.
Tips for Different Roof Types
Asphalt shingle roofs
Shingles get stiff in deep cold and are easier to crack or scuff. Use gentle strokes, leave a layer of snow, and don’t chip at ice stuck to the surface. University of Minnesota Extension notes that raking may damage roofing materials, which is one more reason to rake only when needed.
Metal roofs
Metal sheds snow on its own, often suddenly and in large slabs. Keep people and pets away from the eaves after storms and during thaws. Raking a metal roof from the ground is rarely necessary, and the slick surface makes slides unpredictable.
Flat and low-slope roofs
Flat roofs can’t be reached safely from the ground and don’t shed snow, so drifts and ponding meltwater are common. This is a job for a crew with proper fall protection. If your flat roof leaks after a thaw, see our flat roof repair page.
Garages, porches and sheds
These lower roofs are the easiest to reach from the ground, and they are often the ones that need it most, because they collect drifts and slide-off from the main roof.
What About the Ice?
Raking removes snow, not ice. Don’t try to chop, pry or hammer ice off the roof; it tears up shingles and gutters. Travelers recommends calcium chloride ice melt in a nylon stocking laid across an ice dam to melt a drainage channel, and warns against rock salt, which can damage the roof. If the stocking can’t be placed without climbing a ladder, leave it to a professional.
Repeated ice dams are a sign of heat escaping into the attic. Raking helps in the short term, but the lasting fix is attic air sealing and insulation.
When to Call a Professional
Hire a crew instead of doing it yourself when:
- The snow is out of reach from the ground or over a second story
- Power lines run near the area that needs clearing
- The roof is flat or low-slope
- You see any warning signs of overload
- Ice dams are already causing leaks
- You’re not physically up to heavy, cold-weather work
Our roof snow removal service page explains how a professional crew handles the job. If water is already coming inside, see emergency roof repair. Once the snow melts, a spring roof inspection can catch winter damage to shingles, flashing and gutters before it turns into a leak.
Frequently Asked Questions
Should I remove snow from my roof after every storm?
No. Most Minnesota roofs are designed for heavy snow, so raking is mainly useful after big storms, before rain or a thaw, on low-slope or older roofs, and when ice dams are forming.
How much snow can a roof hold?
IBHS estimates a typical roof can handle about 20 pounds per square foot, which is roughly 4 feet of fresh snow or about 2 feet of old, packed snow. Older or damaged roofs may hold less, so treat these as rough guides.
Will a roof rake damage my shingles?
It can if you scrape down to the surface or pull sideways. Pull straight down the slope and leave 2 to 3 inches of snow on the roof to protect the shingles.
Is it safe to use a ladder to clear roof snow?
No. Ice and snow build up on ladder rungs and boot soles, making winter ladder work dangerous. Work from the ground or hire a professional crew.
Can I use a metal roof rake near power lines?
Avoid it. Aluminum conducts electricity, so use a nonconductive pole near any lines and stay at least 10 feet away from overhead power lines.
Does raking snow off the roof prevent ice dams?
Raking the lower 3 to 4 feet of the roof reduces the meltwater that feeds ice dams, so it helps in the short term. Lasting prevention requires sealing and insulating the attic so heat doesn’t melt the snow.
Clearing roof snow is mostly about knowing when it matters and staying on the ground while you do it. Rake from the edge up, leave a thin layer, keep clear of power lines, and call for help when the job is out of reach.
Need roof snow cleared or winter damage checked? Call (888) 657-0348 for a free estimate.
