Historic Building Turns to New Technology to Avert Wall Collapse
The mortar was just sand (left), so holes were drilled and grout was injected (top and bottom right).
May 6, 2020 — Injecting grout into a failing wall saved a building without displacing residents.
When FSI Architecture was called in for a facade restoration at an aging, Federalist-era building in the Greenwich Village Historic District, architect Julie Georgopoulos got a shock. She found that a load-bearing facade wall at the three-story structure, which has a restaurant on the ground floor and apartments above, was so compromised that it was in danger of collapse.
This was potentially a life-threatening situation. The wall had to be rebuilt, which meant the occupants had to move out. But some of them simply refused to budge. Something had to give.
“We were asked to come in because there had been a series of leaks,” recalls Georgopoulos, a senior project architect at FSI. “But once we started our evaluation and did some probes, we quickly realized the mortar on the load-bearing north wall, which faces the street, was severely deteriorated. It was essentially just sand.”
The simplest fix would have entailed replacing the double-layer brick wall piece by piece from the outside while shoring the floor levels with columns and framing from the inside. But the client wanted a cost-effective solution that would be minimally disruptive to the occupants. “Once we realized how our original plan would affect them – and especially the restaurant – we had to come up with a different solution,” Georgopoulos says.
Forced to improvise, Georgopoulos turned to Masonry Solutions International to see if the wall at the historic building – which dates back to the 1840s and has landmark status – could be strengthened using the company’s new grout-injection technology called CIF, or compatible injection fill. If usable, it would allow workers to rebuild the wall while the building’s occupants remained in their apartments and commercial space.
“Masonry Solutions International had already been getting approval from the Landmarks Preservation Commission for other projects,” Georgopoulos says. “They worked with us to do the inspections, testing and analysis to determine where the voids were in the wall. It turned out there were a lot.” CIF, it seemed, was the way to go.
The process involves injecting a low-viscosity mortar, custom formulated to be compatible with the building’s original masonry, into the wall from the outside to bond the crumbling structure back together. “They drill holes a couple inches apart, starting from the bottom, and just pump it in,” Georgopoulos says. “As it cures, they work their way up.”
Because there was no need for interior shoring, occupants were able to stay in the building for the duration of the north wall project, which lasted eight weeks. Making things even less disruptive, the contractor secured special permits from the Department of Buildings to have all of the work done early in the morning, before the restaurant opened its doors, so it was business as usual.
The client was also very happy with the bottom line. “The money they saved from not having to put up shoring and scaffolding was used for the new injection material, so they broke even,” Georgopoulos says. All things considered, it was a win-win.
PRINCIPAL PLAYERS — ARCHITECT: FSI Architecture. STRUCTURAL ENGINEER: Murray Engineering. GENERAL CONTRACTOR: Adelphi Restoration. INJECTION FILL CONTRACTOR AND MANUFACTURER: Masonry Solutions International. PROPERTY MANAGER: William Gottlieb Management.