It’s January in Iowa, which means the unwelcome return of Iowans’ least favorite winter curse word: Snow.
Unless you’re a seven-year-old going 50 mph down a sled hill, a 4-year-old trying to bring Olaf the Snowman to life, or training to make the U.S. Snowboarding Team for the 2022 Winter Olympics in China, we’re betting you’ve already had enough of the white stuff this winter. Storm-weary Cedar Rapids alone was buried under 11 inches from December 29’s super snowstorm. Johnson County got hit with another four inches from a New Year’s Day storm.
The time-proven rule of winter in Iowa states the obvious: Expect more snow in January and February. Accuweather is predicting a chance for “above-average” snowfall in the Midwest during winter’s second half of the season.
And if you’re a hard-working home roof already stressed out from dealing with the cold of winter, you really hate snow. But how much snow can your roof withstand before it becomes in danger of collapse? It’s a snowy statistic every Iowa homeowner should now.
The snow rule of thumb is most roofs can withstand 20 pounds per square foot of snow. One inch of snowfall on the roof weighs about one pound per square foot. Ten inches of fresh snow equates to about five pounds per square foot. That means the average, healthy American roof can support four feet of fresh snow.
The Federal Emergency Management Agency (FEMA) stresses there are many factors that contribute to snow-induced structural failures, including a roof’s shape, slope, construction, maintenance, exposure to wind, and the type of snow that has accumulated.
Just as Frosty the Snowflake taught us, no two snowflakes are exactly the same and all snows don’t weigh the same. For example, FEMA reports fresh, fluffy snow can weigh as little as three pounds per square foot compared to the bloated 21 pounds of weight wet, heavy snow carries on average.
Climate change and the increased frequency of severe snows has compromised the ability of older homes to withstand snow. Homes built before 1975 may not be structurally sound enough to handle the amounts and types of snows the U.S. will face this winter.
Remember, on average, two feet of snow can equal up to 19 tons (38,000 pounds) of weight on your roof. That’s the equivalent of 115 sumo wrestlers training nonstop on your roof.
“What amounts to a dangerous accumulation of snow on one (older) roof would be just fine on another (newer) roof down the block,” Bob Vila.com’s Steven Fox writes.
Preventing a Roof Snow Avalanche
To avoid your living room turning into a disaster reality movie and suffering a roof collapse, the Insurance Institute for Business & Home Safety recommends homeowners take four steps:
1 – Determine How Much Weight Your Roof Can Support
Most roofs can withstand 20 pounds per square foot of snow.
2 – Calculate the Weight of Snow on Your Roof
Bet you never thought you’d use a snow calculator in high school. Remember, 10 inches of fresh snow equals five pounds per square foot, meaning your roof can likely sustain four feet of fresh snow.
However, packed snow is a different, more dangerous winter animal. Packed snow weighs more. Just two feet of old snow is enough to exceed recommended weight limits. Old snow and new snow can combine to create a combustible mix of too much roof snow weight. Just two feet of each can collapse a roof.
Then, there’s the ice quandary. Throw ice into a heavy roof mix of old and new snow and you have a roof snow moltov cocktail. An inch of snow matches the weight of a foot of fresh snow.
3-Remove Excess Snow and Ice
Remember, your home is not a Thomas Kinkade painting or a snow globe. Clear amounts above 20 pounds per square foot. Snow rakes with long extension arms are recommended. It’s a good idea to remove snow that is 18 inches or more on a low-pitch roof.
Hire a professional contractor to remove excessive amounts of snow and ice for you. No snow storm is worth risking your health.
“The safest path is to hire an insured pro, someone who not only has the proper equipment but also the right experience for the job,” Fox stresses.
4-Clear Signs of Roof Stress
Your roof will tell you if it’s feeling the strain of a snowy winter and needs a roof doctor STAT. Sagging ceiling tiles, sprinkler lines, popping or cracking noises, jammed doors and windows, cracked walls or a leaking roof are all signs of an overstressed roof.
If your roof is damaged and appears in danger of collapse, evacuate your family from your home immediately. Do not risk staying inside or attempt to clean it yourself. Call a structural engineer to access the problem.
Your local building code department can determine if there are specific roof snow weight capacity requirements for your area.
And most importantly, don’t give snow the chance to accumulate on your roof. For a roof snow avalanche is one bad winter dream you don’t want your family to live through.
“Many homeowners wish to take every available precautionary step and shovel snow off the roof before it piles up,” Fox writes. “Not only will this prevent a large load on your roof, but it will also minimize risk of ice dams.”
Taking smart precautionary roof snow steps will also help you and your family avoid uttering winter’s worst curse word.
