Even though your building may have a flat roof, it probably has impediments too, such as heating and cooling equipment, rooftop vents, skylights or solar panels. These provide places for snow to drift, leading to uneven snow accumulations, further affecting the snow load.

If you have questions or concerns about the design of your commercial property—especially if you purchased the building after it was constructed or renovated—you can consult your municipal building and zoning department or a structural engineer. They should be able to tell you how and when the property was built and the applicable snow load in effect at the time of construction. You may need to consider increasing structural support or other changes sooner rather than later.

(AP Photo/Keith Srakocic)

Ice dams and icicles

The roof’s insulation also has an effect on snow loads. As you might expect, a well-insulated roof typically retains more snow than a poorly insulated one or a roof over a poorly ventilated attic. The heat from inside the building doesn’t melt the snow on the well-insulated roof, which can cause ice dams.

An ice dam creates a concentrated load at the eaves and limits how well snow can slide off a sloped roof. On flat or low slope roof systems, snow melt often accumulates in low areas. If the roofs are poorly designed or the drainage systems are blocked, you may have ponding, which creates a concentrated load on the roof structural system and a potential hazard.

Ice dams and melting snow also can cause icicles to form. Whenever you’re removing snow or ice from a roof, be careful of knocking icicles off. An icicle falling from a short height can still cause damage or it may injure someone below.

Warning signs of collapse

Roof collapses generally don’t happen overnight. According to FEMA, the following warning signs are common in wood, metal, and steel constructed buildings:

• Sagging ceiling tiles or boards, ceiling boards falling out of the ceiling grid, or sagging sprinkler lines and sprinkler heads
• Sprinkler heads deflecting below suspended ceilings
• Popping, cracking, and creaking noises
• Sagging roof members, including metal decking or plywood sheathing
• Bowing truss bottom chords or web members
• Doors and/or windows that can no longer be opened or closed
• Cracked or split wood members
• Cracks in walls or masonry
• Severe roof leaks
• Excessive accumulation of water at non-drainage locations on low-slope roofs

Between snow storms and before a thaw, it’s important to inspect drains, gutters, downspouts and vents for snow or ice blockage from your latest accumulation to minimize damage and prevent a possible roof collapse.

Where to put the snow

Snow load is a factor in snow removal as well as in collapsing roofs. The snow from a storm might be within load limits, but when you move the snow to one section of the roof, you may be exceeding the limits for that area.

Be careful when dumping the snow off the flat roof, too. You’ve probably seen people push snow from a parking garage deck onto a parked car below, for example, resulting in significant damage. The falling snow also can cause serious injury if a person walks by at the wrong time.

Related story: Do’s and don’ts for safely removing snow from your roof

The area you’ve designated for snow removal needs enough capacity to accommodate the additional snow. For example, the mound of snow at the Portland, Maine, airport that was pushed off the runways reportedly was close to reaching the Federal Aviation Administration height limit, requiring the airport to find a second dump site.

Target was sued after a customer fell as a result of the accumulated snow and ice mounded in a store’s parking lot. Although the general rule in many states is that the premises owner isn’t liable for a “natural accumulation”—that is, untouched snow on the ground from a storm—the owner is liable for snow mounds created by plowing, which leads to an “unnatural” accumulation, according to some courts. In another case, a property owner was sued for doing a bad job of removing snow from the steps leading into the building when there was no obligation to remove the snow at all.

If you’ve created snow mounds in your parking lot, but there is so much snow that you can’t park cars or drive safely, you may need to transport the snow offsite to a snow farm or rent a snow melter.

Insurance coverage: Basic Form or Broad Form?

If your property is insured under ISO CP 10 10, the Causes of Loss—Basic Form, you have named perils coverage, which is the most limited, according to Donald S. Malecki, CPCU, author of the Commercial Property Coverage Guide, 5th Edition. Only those perils specifically included in the form are covered, and loss or damage must be directly caused by the named perils, which include windstorm and hail.

Generally, under this policy, before windstorm or hail damage to the interior of a building is covered, the exterior must be damaged directly by the wind or hail. After such damage to the exterior of the building, the policy covers the interior for damage caused by rain or snow entering the structure. A common type of claim reached by this exclusion, says Malecki, is water damage to walls, ceilings, or personal property that occurs during a windstorm but for which there is no apparent source. Sometimes this type of damage results from seepage around window casings or eaves because without some kind of damage, even though it’s temporary, water would not have seeped through the window or ceiling.

What is excluded from coverage?

If your property is insured under ISO CP 10 20—Broad Form Causes of Loss, coverage for damage from a windstorm or hail excludes damage from

• frost or cold weather,
• ice (other than hail), snow, or sleet, whether driven by wind or not, and
• loss or damage to the interior of a building or structure (or the property inside) caused by rain, snow, sand, or dust, whether driven by wind or not.

However, as with the basic form, the loss may be covered if wind or hail damages the roof or walls of the building or structure through which the rain or snow comes in.

Weight of snow, ice, or sleet

The weight of snow, ice, or sleet peril applies to all covered property other than personal property outside of buildings or structures and, as introduced with the 2012 revisions, loss or damage to lawns, trees, shrubs, or plants that are part of a vegetated roof, Malecki explains. The broad form also provides coverage for gutters and downspouts from the weight of snow, ice, or sleet.

You may have coverage for a plumbing rupture caused by freezing as long as you maintain heat in the building or structure or you’ve drained the heating equipment and shut off its water supply (generally for vacant buildings). Coverage for water damage doesn’t apply after the building has been vacant for 60 days.

If a power failure, power surge or other utility service interruption results in a covered cause of loss, that damage is covered. For example, if a power failure shuts down your heating system, which causes pipes to freeze and rupture, and the broad causes of loss form applies, resulting damage is covered.

(AP Photo/Mike Groll)

Collapse

Collapse is not a cause of loss but rather the result of a covered cause of loss, Malecki says. When two independent causes of loss converge on covered property, one that is excluded and the other that is covered, the entire loss is covered. The building isn’t required to fall into rubble to be considered a collapse; instead, if the building is in imminent danger of collapsing, coverage is triggered, he adds.

The broad form covers a building against collapse caused by listed perils. Although the Building and Personal Property Coverage Form (BPP) applies to both buildings and structures, collapse coverage applies only to buildings or to part of a building. Under the BPP, the weight of snow, ice or sleet and water damage to a building is covered, but structures are not covered.

The following are not considered collapse under the BPP:

• a building that is only in danger of falling down or caving in.
• a part of a building that is still standing, even if it has separated from the rest of the building.
• any building, or part of the building, that’s still standing, even if it shows evidence of cracking, bulging, sagging, bending, leaning, settling, shrinkage, or explosion.

The form defines water damage as the accidental discharge or leakage of water or steam as the direct result of the breaking apart or cracking of a plumbing, heating, air conditioning or other system or appliance (other than a sump system including its related equipment and parts), that is located on the described premises and contains water or steam.

Review your policy

If you own a commercial property, and you’ve escaped significant damage in the winter of 2015, you’re to be congratulated. As a precaution against damage from the spring thaw or future severe winter weather, you should read your policy carefully to understand what coverage you have and don’t have, and discuss your options with your broker and risk manager. Risk mitigation is always in season.