Snow Loading Warning
March 24, 2011
HIGH SIERRA RESIDENTS AND BUSINESSES SHOULD MONITOR SNOW LOADS ON ROOFS, PROPANE TANKS, NATURAL GAS LINES AND BUILDING VENTILATION SYSTEMS
Placer County public safety agencies are advising High Sierra residents and businesses to monitor buildings, propane tanks and natural gas lines for signs of excessive loading due to heavy snow loads.
Residents and businesses also should monitor roof vents, chimneys and flues because they need unobstructed access to outside air to provide proper ventilation. Blockages can lead to carbon monoxide build-up in buildings. The heavy snow loads may cause chimneys to shift.
Particular attention should be paid to buildings constructed before Placer County adopted snow-load standards for North Lake Tahoe and other High Sierra areas in the early 1960s.
Snow loading is expected to continue through the weekend.
Local agencies also are reminding residents and businesses to properly care for propane tanks and natural gas lines because the extraordinarily deep snowpack can damage pipes, valves and tanks, leading to leaks.
Anyone who smells propane or natural gas inside or outside a building should call 911. They also should avoid smoking, starting engines or motors, turning on cooking appliances, using heating-air conditioning systems or using other ignition sources.
The Building Services section of the Placer County Community Development Resource Agency says potential snow load danger signs include:
· Sagging of beams and other parts of a building’s structural-support system.
· Newly developed cracks, particularly any that appear above windows or doors and where beams and other support structures are located. Minor cracks that expand or contract could be indications of building movement.
· Doors and windows that have recently become significantly harder to open or do not open at all, a sign that a building is settling because of a heavy snow load
· Serious water leakages inside buildings.
· Recent buckling of interior or exterior siding and finishes, which may be a symptom of settling due to snow loads.
Generally, residents and business owners are not encouraged to try to clear their roofs when the snow load is so heavy. Potential dangers include injuries caused by falling snow; roof damage caused by removing snow from some areas, but leaving heavy snow loads in others; and electrical hazards from coming into contact with overhead power lines and electrical service drops that are no longer visible.
Residents and businesses also are being advised not to increase temperatures inside buildings, hoping to melt snow on their roofs. The result typically is a layer of ice between the roof and snow pack.
Residents and businesses concerned about the snow loads on roofs may want to seek the advice of roofing contractors, general contractors or structural engineers.
For homes at elevations above 5,000 feet, residents and businesses with propane questions should contact either their propane suppliers or local fire agencies. For natural gas questions, contact suppliers.
Safety tips for the proper care of propane tanks during severe weather are on the county website at http://www.placer.ca.gov/News/2011/March/Propane.aspx. The website also contains advice for natural gas users to follow when they smell gas odors.
Placer County recommends that property owners and managers keep contact information, including home and cell phone numbers, current with gas suppliers, homeowner associations, and neighbors. In a gas emergency, it is important that emergency personnel be able to contact affected property owners.
Checking ventilation system is critical because heavy snowfall can damage roof vents, chimneys and flues.
Blockages can cause combustion waste products to back up in homes and businesses. One of these waste products, carbon monoxide is potentially lethal.
Operating generators during power outages and alternative heating can also create problems if not used properly. When using portable generators, keep them outdoors and far away from open doors, windows, and vents to avoid toxic levels of carbon monoxide from building up indoors.