Can Your Roof Withstand Winter’s Snowy Fury?

Your roof is your home’s first and most important line of defense against winter’s biggest and costliest headache: Snow.

If winter’s many storms give you migraines, imagine how your roof, the most essential part of your home’s construction, feels. For every blizzard dropping 10-12 inches of new snow (equal to one inch of water), your roof is holding up not just your home, but five pounds of snow per square foot. For most modern homes, one blizzard isn’t too much for a roof to handle. But when forced to bench press the weight of several blizzards (four feet of snow), even the most cutting edge, severe-weather proof roof can become stressed.

Just think of the stress the roofs of the Boston area must have been under during Bean Town’s record 100-inch snow season of winter 2014-15. The National Weather Service reported “hundreds of major roof collapses and structural failures” during the 65-inch snow blitzkrieg the New England area received between January 27 and February 11, 2015. The price tag was enormous. In America, the average cost of installing a new asphalt roof is $6,000.

To get a good read on how much stress your home’s roof may be under during winter’s snowiest days, here’s how the weight metrics of roof snow break down:

  • Packed Snow: 3-5 inches of old snow is equal to one inch of water, or five pounds per square foot of roof space. By the time your roof takes on its fifth snow of the season with no melting, it could be holding up up to two feet of old snow – a cumulative weight that especially puts older roofs in structural jeopardy.
  • A Winter’s Worth Of Packed Snow: This is the situation Boston found itself in during early March 2015 after three months of unrelenting snow. Two feet of old snow and two feet of new snow can put as much as 60 pounds per square foot of pressure on your roof. This is well beyond the snow load capacity of most roofs.
  • Ice: The only thing more stressful on your roof’s structural integrity than snow. One inch of ice equals one foot of fresh snow. Ice damming occurs when the sun melts the lowest layers of snow against the roof. The water then runs down shingles into gutters and freezes again. As ice builds up in gutters and downspouts, it prevents roof water from running off the roof. When this happens, melting snow works its way back up and under shingles, leading to leaks in the attic and down into ceilings and walls.

Whether your roof can sustain a heavy snow load without damage or collapse depends greatly on the depth and density of the snow along with the depth and spacing of its rafters and trusses, roof surface slope and texture, and the shape and location of rooftop snow drifts.

Which Roofs Are Most At Risk To Winter’s Snowy Wrath?

Unlike wine, not all roofs get better with age. And older roofs are naturally more likely to face structural integrity issues when holding up large amounts of winter snow.

Eighty percent of today’s modern roofs are constructed out of fiberglass shingles, which are built to handle heavy snowfalls. Roofs that are most able to withstand heavy amounts of snow have smooth and steep designs (allowing snow to slide off) and framed with closely spaced rafters. Roofs in sheltered areas also have a greater chance of snow settling on them evenly, preventing wind to blow snow into heavy drifts that can lead to unequal snow weight distribution and cause roofs to fail.

Other roofs at greater risk for collapse are older structures and roofs that are flat, slightly pitched and in open locations where they are exposed to the wind. Shallow roofs that stand adjacent to or below taller, steeper roofs are extremely vulnerable to snow loads sliding down onto them. This blowing snow effect  can also target low-sloping roofs over porches, carports and lower-standing home additions.

The Roof Rake: The $40 Roof Snow Removal Solution

Never try fighting roof snow with a standard snow shovel. It’s dangerous, too heavy and the process would take forever (raking leaves is a fast job in comparison).

Available for $40 on average at hardware stores, a roof rake allows you to safely remove large amounts of snow from your roof. Roof rakes can be handled from the ground and operate like a long garden tool with a 16 foot handle.

Be sure to snow rake both sides of your roof to avoid uneven snow distribution and leaving a lopsided amount of snow staying on one side of your roof. Remember, a snow rake won’t completely rake your roof free of snow (especially after several storms in rapid succession) but it will remove the threat of snow structurally compromising your roof.

Use a roof rake any time your roof takes on two or more heavy snows (3-5 inches of snow) within a week.

Other measures to take and remember before winter’s first snow blows in:

  • Insulate The Attic: Attic insulation keeps heat in the interior of the home and minimizes temperature fluctuations on the roof.
  • Leak Proof The Attic: Remember, the attic is the last line of defense between water and the ceilings of your home. Have your attic professionally inspected for leaks in November to ensure there are no outlets for water to penetrate the interior of your home.  If you notice leaks or water marks on the walls or ceilings during the snowy heart of winter, the damage has already been done and it’s time to call in a Restoration 380 professional.
  • When In Doubt, Call In The Experts: Again, consult a roofing professional to deal with ice dams, gutter back ups, extreme roof snow buildups and other winter roofing emergencies.

Knowing how winter’s snowy flurry can attack and threaten your roof’s structural integrity can help you snow guard your roof from structural and financial disaster.

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