Heavy, Wet Snow Creates Roof Collapse Hazard
GRAND RAPIDS, Mich. — Almost 80 inches of snow has fallen in Grand Rapids so far this winter and with more on the way Saturday the heavy snow is causing problems for some structures. Heavy, wet snow falling Saturday morning will add to the 18 inches of snow already on the ground in the city and reports of roofs collapsing, like this one at the offices of the West Michigan Tourist Association in Grand Rapids are becoming more common.
This winter’s above average snow and ice puts pressure on roofs and while some structures are more susceptible than others, complete roof failures are becoming more of a hazard as the snow continues to pile up. Most roofs are built to withstand the force of 20 pounds per square foot. Typically, that would mean your average roof should remain in tact with up to 4 feet (48 inches) of snow. Add ice and compacted snow and that threshold falls to 3 feet (36 inches) of ice and snow. Low pitch or flat roofs have much less of a weight threshold and that is where we are starting to see the danger as additional heavy, wet snow accumulates.
With an average of 18 inches on the ground and the possibility of another 3 to 6 inches of dense, heavy snow possible Saturday that will increase the threat to old, damaged or low-pitch roofs. Roofing professionals recommend using a roof rake to remove excess snow to prevent any problems as snow and ice continue to accumulate.