Leave the job of clearing excessive snow and ice off of roofs to trained professionals, said the American Society of Safety Engineers (ASSE) President Samuel Gualardo.
Shoveling snow off roofs is hazardous because it easily possible to slip off of a roof or ladder.
"We strongly discourage anyone without the proper and necessary fall protection equipment to clear snow off of roofs," said Gualardo. "The average home or business owner does not have the proper equipment or training.
"However, if person is absolutely bent on doing something about ice accumulation," said Keith Vidal, ASSE Standards Development Committee chair. "appropriate measures must be taken, such as never stepping onto a sloped roof, or in some cases an icy flat roof, unless the person uses the appropriate fall protection equipment, which includes a harness and lanyard."
According to ASSE, when using a ladder, make sure it is set at the correct angle with the bottom feet of the ladder approximately one fourth of the distance from the foot of the ladder straight up to where it is supported by a wall or roof edge.
The bottom of the ladder must be secured in position to avoid slipping away from the wall or building and the top of the ladder must be tied off so that the ladder cannot fall away, fall sideways or slip away from its support, Vidal noted.
When climbing onto a roof using a ladder, make sure that the ladder extends approximately 3 feet over the supporting edge, not more or less, said Vida.
He also said it is extremely important to note that even when a second person stabilizes the ladder at the bottom all of the above safety measures should be used.
Of additional concern is that none of the above measures consider the actual load strength of the roof, which must also be considered on all structures, noted Vidal.
"Only a qualified engineer should make this decision, as the structural load capacity of many roofs is being approached with the amounts of snow and ice that are one them," said Vidal.
Vidal strongly recommended against spreading ice-melting chemicals on a roof because it could cause damage to the roof and drainage system and is ineffective as a measure to reduce the amount of snow and ice on a roof.
"The bottom line is: people are taking a serious risk when undertaking roof clearing activities under wet, slippery and cold conditions," said Vidal. "A fall from a roof can change a persons life forever."
by Virginia Sutcliffe