About half of the projects undertaken by Len Scannapieco's company, Estate Homes, are commercial. These tend to be renovations of older buildings. What that means, says the contractor, is that anything could happen, and he needs to be on site much of the time to deal with emergencies. "It's one of the elements that makes working on old structures so challenging."
And unpredictable. On the Boiler House, for example, demolition took weeks instead of days because "we were trying to maintain the integrity of the building and reconstruct it at the same time." The plan was to leave intact the steel frame supporting the brick shell, while removing the roof, some walls, and parts of walls.
The original shell consisted of open space with only a ground floor. The concrete platforms and tables on which the power-generating equipment once rested were jackhammered apart and the pieces taken away. Then two adjacent walls facing the chimney, 56 feet high, needed to come down. They were removed "steel beam to steel beam," says Scannapieco, "so we had a good deal of support left throughout the structure as bricks fell."
The next major phase of demolition involved removal of the roof structure, then the spandrel panels, which were taken down brick by brick. The design called for replacing the spandrel panels with a Dryvit exterior insulation and finish system.
"The biggest precaution is not to allow too large a mass of masonry to fall, due to the movement that could occur," Scannapieco says.
When air pockets were found under the concrete floor, foundation work was held up a week while an engineer investigated the problem and recommended a solution. "To maintain the schedule and control costs, you have to be available," Scannapieco says. "You can't deal with situations when they're discovered unless you're there. "