Snow is pretty. Snow is fun. Snow is dangerous. All of these things are true.
For homeowners, snow buildup is the most dangerous aspect of snow. Why is it important to avoid snow buildup? First, that snow’s gonna melt eventually. It needs to drain somewhere. That could lead to ice dams or flooding. Second, snow buildup can be tremendously heavy, potentially damaging your roof. Third, snow buildup can block doors and windows. Do you really want to find yourself in a situation in which you can’t get in or out of your own house?
So what should you do to prevent snow buildup? And what can you do if it’s already happened? Covered breaks it all down, explaining the problems, preventative measures, and just-in-time solutions for each situation. After all, while we’re happy to remind you that the property damage caused by snow buildup may be covered by your homeowners insurance, isn’t it better to avoid the damage in the first place?
We thought so. Read on for everything you need to know about avoiding and dealing with snow buildup.
Getting to Know Your Snow
Before we begin, let’s make sure we understand the literal weight and volume of the potential problem. How heavy is snow? And how much water can snowmelt produce?
How Much Water Is in Snow?
NASA gives a 10:1 average ratio snow volume to water, meaning that — on average — 10 inches of snow will produce 1 inch of water. But the answer ultimately depends on what the snow is like, as well as the air temperature where the snow is melting.
Unsurprisingly, lighter, drier snow produces less water, and denser, wetter snow produces more water. This National Oceanic and Atmospheric Administration (NOAA) table gives estimates for melt water produced by snowfalls at different temperatures.
How Heavy Is Snow?
According to the Snow Load Safety Guide published by the Federal Emergency Management Agency (FEMA), one foot of fresh, light, dry snow may weigh around 3 pounds per square foot (PSF), while one foot of wet, heavy snow can weigh up to 21 PSF. So — because we’re in the land of insurance, which means we’ve occasionally got to contemplate those worst-case scenarios — let’s look at what that might mean for a home with a 1,500 SF roof:
- 1 foot heavy snow = 1,500 SF X 21 PSF = 31,500 pounds = 10 average-weight female hippos
- 2 feet heavy snow = 1,500 SF X 42 PSF = 63,000 pounds = 5 average-weight African elephants
- 3 feet heavy snow = 1,500 SF X 63 PSF = 94,500 pounds = 7 average-weight African elephants and at least 3 average-weight female hippos
Do we have your attention, now that you’re picturing all that wildlife clomping around on your roof? Excellent. Let’s move on to the various ways snow buildup can be dangerous for homeowners — and what you can do about it.
1. Roof Snow Melt = Potential Ice Dams
WHAT’S THE PROBLEM? Family Handyman offers a great diagram and description of how ice dams form, and how to avoid ice dams. In a nutshell, ice dams form when heavy snow meets a warm roof. The warm air in your attic causes snow to start melting. When snowmelt runs down the roof and hits its colder edges, it refreezes, forming an ice mound. That’s an ice dam, which can trap snowmelt — potentially leading it to seep into the shingles, rot your roof, drip into your home, and stain your walls and ceilings.
PROACTIVE SOLUTIONS. To prevent an ice dam, you need a consistently cold roof. Check out the Family Handyman link above for a step-by-step guide to avoiding ice dams. It involves closing up attic bypasses, checking the depth of (and potentially upgrading) attic insulation, and adding roof vents. You can also consider installing heat cables or ice-and-water barriers near roof edges.
JUST-IN-TIME SOLUTIONS. After a heavy snowfall, rake or sweep the snow off your roof. A fit-for-purpose roof rake works best. You can also toss large salt tablets up onto the roof to help prevent an ice dam from forming. What to do if you already have an ice dam? If an ice dam has already formed, it’s best and safest to call in a professional roofing company to steam it off.
2. Roof Overload = Potential Damage or Collapse
WHAT’S THE PROBLEM? When the weight of accumulated snow is in excess of what your home was designed to support, your home’s roof and structure could be at risk of damage or even collapse. While FEMA states that “most buildings are not at risk of snow-induced failure,” it’s important to understand the risks. In particular, unbalanced snow loads — in which snow accumulates at different depths across your roof due to drifting and sliding — are higher-risk than uniformly distributed loads. Roof geometry, features (e.g., parapets, chimneys, solar panels), and wind exposure are the primary factors impacting your risk of slides and drifts. Ice dams can also lead to uneven accumulation.
PROACTIVE SOLUTIONS. Follow the guidance to prevent ice dams (see above). Consider installing snow guards or cleats to keep snow from sliding from one portion of your roof onto another. Frequently inspect gutters and downspouts for blockage, and regularly inspect the roof for signs of damage, deterioration, or weakness. Enlist a qualified professional to inspect your structure for warning signs.
JUST-IN-TIME SOLUTIONS. If you see warning signs that your roof may already be overloaded, you should immediately (1) evacuate and (2) contact a qualified professional to conduct a detailed inspection. They can assess the building’s structural integrity and determine what’s required to make the building safe again. Warning signs include sagging ceiling tiles, boards, or roof members; doors and windows that can’t be open or closed; severe roof leaks; cracks in walls or masonry; cracked or split wood members; excessive water accumulation on low-slope roofs; and popping, cracking, or creaking noises.
3. Melting Snow = Potential Flooding
WHAT’S THE PROBLEM? When snow melts, the resulting water needs to go somewhere. Upon hitting your home’s foundations, snowmelt starts running downward. And that concrete foundation… is porous. Even if it looks like just a small amount of water has made it inside, there could be lasting damage. Wet walls can weaken and ultimately crumble or collapse. Even worse, toxic black mold could begin to grow — and mold damage may not be covered under your homeowners insurance.
PROACTIVE SOLUTIONS. Inspect your home’s foundation and basement walls for cracks. If you find any substantial ones, seal them up with epoxy. (If you find any REALLY big ones, you’re better off investigating concrete repair options.) When landscaping, ensure that the ground slopes away from your home. If you don’t already have one, consider installing a sump pump. You can also consider hiring a professional service to waterproof your basement.
JUST-IN-TIME SOLUTIONS. After a big snowfall, use your roof rake to remove snow and icicles. Then, use your snow shovel or blower to clear a five-foot radius around your home. That will prevent most snowmelt from reaching your foundation. What to do if snow melt is flooding the basement already? Turn off the electricity to the area and call a professional ASAP. They’ll use professional water extraction systems, drying equipment, dehumidifiers, and sensors to dry out your basement.
4. Blocked Stairways or Doors = Potential Safety Hazard
WHAT’S THE PROBLEM? Nobody loves shoveling. But if you let snow build up in front of your doors or on your stairways, you may not be able to get in and out of your home safely. You could also end up injured, slipping or falling on the accumulated snow and ice. Drifting snow is often the real culprit, as wind blows piles of snow up against your home.
PROACTIVE SOLUTIONS. Keep a snow shovel and pourable jug of pet-safe ice melter near your door. When it snows, promptly shovel and distribute ice melter, keeping buildup from happening. Repeat as needed. You can also consider a temporary snow barrier to help prevent snow drifts from forming.
JUST-IN-TIME SOLUTIONS. What to do if your doorway is blocked by snow already? First, make sure you have another way to get out. Check other doors and windows. Then, start shoveling out the blocked door from the outside. If you can’t find a way out, it’s time to call someone to help dig you out.
Looking for another way to be a smart, proactive homeowner? Make sure you have the right homeowners coverage at the best price! Covered’s expert insurance advisors will be happy to do a free policy review. Just give us a call at (833) 487-2683 or send us a message.