Snowed Down
May 03, 2022
By: Monica Roselli
At 3 p.m. on a Friday in February 2021, NDA member Empire Services received a call from the city of Reading, Pennsylvania, to perform an emergency demolition after a snowstorm caused the roof and upper floor of a three-story structure to collapse a mere 4 feet from power lines on the 200 block of Maple Street. If not stabilized and demolished immediately, the snow load, combined with years of structural deterioration, could make for a large power outage that would leave many without utilities in freezing winter temperatures.
Because of its previous experience managing unique hazards associated with demolishing damaged and partially collapsed buildings, in addition to its specialty equipment and dedicated staff, Empire was chosen for the job. While the city of Reading was still removing snow, Empire began to mobilize personnel and equipment.
“During an emergency call, the first thing that must happen, once you get your equipment on-site, is to begin stabilizing the building,” says Empire Services Project Manager Matthew Bard. “You need to get the additional weight of the collapsed material off the exterior walls and floors as soon as possible to take pressure off the already damaged structure. The sooner this is done, the greater the reduction of risk of any additional structural failure becomes.”
Once Empire was able to mobilize the needed equipment and manpower, an 85-foot articulating boom man lift was positioned and used to get above the structure so that the building’s condition could be evaluated and a demolition plan created.
The demolition strategy for the building was unique in several ways. “Due to the close proximity of high-tension electrical lines immediately adjacent to the building, two adjacent streets with housing on the opposite side and an additional structure directly against the southern wall, the building had to be approached from the north and demolished by working toward the southern side of the structure,” Bard says. “The overall strategy was to work the building from top to bottom, using brick and block from the structure to fill in the basement as we went in order to provide a stable work area and allow for the excavator to have the proper reach to continue demolition while still being able to maintain a safe working distance.”
Demolition began on the damaged section of the building using a John Deere 350 ultra-high reach excavator equipped with a grapple. Small sections of exterior brick walls, beams and other debris were systematically demolished to remove pressure from the building.
Working throughout the night to stabilize the building, Empire was able to coordinate efforts with the city to ensure that water, gas and electricity on the adjacent sidewalk and in the adjacent street were protected. Empire was also able to coordinate readily available utility crews to assist in case of a further collapse. Empire additionally worked with the local electric company to relocate the high-tension power lines next to the building, the closest of which was 3 feet away, to the other side of the utility poles so that demolition could safely continue.
Before demolishing the southernmost sections of the building, the structure was removed by hand from an attached structure that was to remain. Additionally, the basement slab was broken up, and the site was graded with the broken brick materials to help promote drainage. In closing out the two-month-long project, new framing, insulation and siding were installed along the edge of the roof of the building to remain, and the site was given a final cleaning before the crew demobilized.
The job was a success according to Bard. Empire was not only able to overcome the challenge of working in an extremely tight, urban space without causing damage to the surrounding streets and structures, it was able to leave all surrounding utilities intact for the duration of the project.
Insight Into an Urban, Partial Collapse
“When performing demolition in an urban environment, the crew must be patient. Demolition must be precisely planned and methodically executed because of the number of exterior factors impacting the work. There are other structures, residents, streets and utilities that can all be dramatically impacted if any mistakes are made. This becomes exponentially more challenging when dealing with a structurally impacted building because the risk of additional collapse or a building shifting during demolition sending debris into the road, onto other adjacent buildings or properties increases.” —Allen Dejewski, Vice President, Empire Services