To identify potential structural overloading and associated hazards during and immediately after the snow, some symptoms may include (but are not limited) to the following:
If you notice any of these issues at your home or office, we recommend that you leave the property immediately, and if you are in a multi level property, notify the people adjacent to and below you as well. Then when it’s safe, you should consult Kipp Gaynor from the Structural Rehabilitation Group, a local Structural Engineer at 301-300-8700. Or visit their web site at: http://SRG-LLC.net
Unfortunately the minimum weight load codes in Maryland are not as high as you would expect. Plus with high wind and drifting snow most of the roofs will have unbalanced roof loads, as shown in this photo.
Here are some specifications that I found and links to them that I thought were a little alarming:
1607.12 Minimum Roof Live Loads. Roofs shall be designed for a minimum live load of 20 pounds per square foot or designed for the minimum snow load, whichever is greater.
Now here is a quick calculation that explains why property owners in Maryland should be concerned about heavy accumulations of snow on roofs.Quick Snow Load calculation
This calculation is based on a 25% moisture density which may be conservative for the current snow fall. As a rule of thumb, saturated snow weighs approximately 20 pounds per cubic foot. The moisture content of snow can range from approximately 1% to 33%, which relates to snow potentially weighing from 1 pound per cubic foot to over 21 pounds per cubic foot for really “wet” snow.
Calculation: Snow x 1.25 = P where:
Snow = Inches of snow on the roof (depth)
1.25 = Weight of 1 sq ft of snow for each 1-inch of depth
P = Pounds per square foot (lbs/sq ft)
So if the snow on the roof is only 20-inches deep it could weight up to 25 lbs per sq ft of snow, which is pretty close to Maryland’s minimum roof load!
This isn’t the only concern you should have about heavy accumulations of snow on roofs either. After the storm passes, the next thing you need to be on the lookout for is ice dams forming on the roof.
An ice dam is a buildup of water that is formed from Heavy Accumulations Of Snow On Roofs as it melts, then runs down the slope of the roof and then forms into ice near the outside wall of the house. This is usually at the soffits where there is slightly cooler air because its located past the heated areas of the home, but where cooler air is drawn into the attic from the vents in the soffit. It may only be a difference of 1 Degree but if temperatures are low enough, that’s all that’s needed for the water to freeze. Through constant fluctuations in temperature, a wall of ice is formed across the roof and water begins to build up behind it. Once the pond of water behind the ice dam is deep enough, it starts to back flow into the exterior walls of the house. Ice dams are usually formed very slowly, and it usually requires Heavy Accumulations Of Snow On Roofs for them to form over a day or two. Then the water that is leaking into the walls starts to become noticeable. When this happens it can cause water damage to the walls and ceilings of every floor of the house below it, so you should contact us for snow and ice dam removal.