With another series of storms due this week, Placer County public safety agencies urge Sierra Nevada residents and businesses to keep an eye on buildings, propane tanks and natural gas lines that may suffer from heavy snow loads.
Roof vents, chimneys and flues can become blocked by snow buildup and must be cleared to provide proper ventilation. Blockages can result in buildup of carbon-monoxide, creating potentially unsafe indoor conditions, according to a Placer County news release. Heavy snow also can cause chimneys to shift and possibly fall on people below.
The news release said particular attention should be paid to buildings constructed before the county adopted snow-load standards in the early 1960s. Even newer buildings designed to handle average snow loads are at risk when exceptional accumulations of snow exceed design limits, the release noted.
Propane tanks and natural gas lines and valves can be damaged by deep snow pack, resulting in leaks. The news release noted that propane is heavier than air and settles to the ground, while natural gas is lighter than air and rises. Anyone who smells propane or natural gas inside of outside a building is advised to immediately call 911, and to avoid smoking, starting engines or motors, turning on cooking appliances, or using heating/air conditioning systems.
Danger signs of potentially heavy snow loads, according to Placer County’s Building Services Division, include:
- Visual deformation or sagging of beams or other parts of the building’s structural support system.
- New 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 indicate building movement.
- Doors and windows that suddenly become much more difficult to open or do not open at all are a sign that a building may be settling.
- Water leakages inside buildings.
- Recent buckling of interior or exterior siding and finishes, which may be a sign of settling.
- Sprinkler heads pushed down below ceiling level.
If there is any doubt about the integrity of a roof in heavy snow conditions, the building or area should be cleared and the advice of a professional sought, according to the news release.