How much snow on South Lake Tahoe roofs is too much? Two local buildings damaged with cave-ins

SOUTH LAKE TAHOE, Calif. - One of the signs of near record amount of snow around Lake Tahoe is the height and weight of snow on the roofs of all buildings. This week there have been two buildings that suffered damage on the South Shore as the roofs caved in after the snow load became too much.

What is too much?

South Lake Tahoe Fire Rescue (SLTFR) responded to a structure collapse Wednesday on Melba Avenue. The heavy snow flattened the building as three of the four walls pushed out because of the load, leaving just one wall standing. Lake Valley Fire responded to a home on Cold Creek Trail that experienced a partial collapse on the same day.

SLTFR says a basic rule of thumb is to look at removing snow when it gets to be three feet high, though there is no "one size fits all" rule and some roofs can hold much more.

Many factors come to play: water content in snow, the slope of the roof, and the pounds per square inch the home can hold.

South Lake Tahoe and El Dorado County homes at the lake have a minimum requirement for roof snow loads at 150 pounds per square foot, but each home is different. For those in El Dorado County, visit https://parcel.edcgov.us/, enter parcel number and the roof load can be found. Some new homes are engineered to hold much more than 150 pounds per square foot.

There are formulas a structural engineer can determine, but for basic snow removal, the resident can look for telltale signs - doors that stick when opening and cracks in the ceiling, as well as a high amount of snow.

The snow that fell this week had low water content, but as the snow melts, then refreezes as ice, that amount on the roof can get heavier.

SLTFR Chief Kim George said she expects to see more collapses this winter, and she is concerned about mobile homes that cannot hold heavy snow.

There have been different building standards over the years, and the City of South Lake Tahoe's Director of Development Services Hilary Roverud said they cannot do blanket structure rules since all homes are different.

"Every snowflake is different," said Roverud. Water content determines the weight of the snow, just as every roof is different.

Many residents are shoveling the snow off their roofs or hiring someone to do the task. Chief George said there are handy tools to use when the snow is still soft and light, such as the Snow Peeler. This device goes into the snow, and a shoot brings the snow down to the ground.

Long-time resident, Duane Wallace has been a lot of snow during his decades in both Sonora and South Lake Tahoe. He gives these rules for removing snow off the roof, many of which he says he learned the hard way:

If your doors become hard to open from the weight, it’s time to clear the snow from your roof.

Shovel both sides of your roof equally as you clear the roof because if you shovel one side first the incredible weight of the load on the other side may cause the roof to pry loose from the nails causing a tilt of the roof.

Never shovel too close to the edge of a roof where you won’t survive a fall.

Remember that ice forms near the eves which creates a dangerous slide.

Shovel with a partner in case of an avalanche off the roof.