Aging Building Faces Major Structural Repairs After Sagging Floors Discovered

What began as a simple apartment sale at a 160-unit HDFC in South Harlem snowballed into major structural repairs. A shareholder wanted to sell her apartment, but there was a problem: the floors were sagging. A closer look uncovered several broken beams beneath the floorboards, which was bad news for the board. “We had to rip out the entire apartment and gut it so we could get to the beams under the floor,” says Josh Koppel, president of H.S.C. Management, the company that manages the building. 

The apartment sale at the prewar building was put on hold while the beams were repaired. 

Sagging floors are not uncommon in prewar buildings with wood framing, says Eugene Gurevich, a senior structural engineer at RAND Engineering & Architecture, who has expertise in this area but was not involved in this specific project. “The first thing to do is notify the co-op board and engage a structural engineer to evaluate the conditions,” he says.

In these situations it’s helpful to have an experienced super or maintenance team who knows the history of the building. Sagging floors don’t always indicate a building-wide problem, and it’s important to find out if load-bearing walls have been removed in the apartment below, which increases stress on the beams and joists above. In this case, the beam deterioration wasn’t the result of alterations but simply the building’s age. “I don’t see how it could have been prevented,” Koppel says. 

When the beams and joists of the floor framing are compromised, problems such as cracks on the walls and twisted door frames often result. Visual investigations and probes at the five-story co-op resulted in a scope of work that involved pulling up the flooring and subfloor — the plywood layer beneath — to access and replace the broken beams. This involved a process called sistering, where framing is reinforced by attaching new, similar sized beams to the original material. “You double the strength or at least return the original strength of the framing,” Gurevich says. 

The floor repairs came with additional headaches. The position of plumbing lines, which obstructed the beam replacements, complicated the repairs. Pipes needed to be relocated to accommodate a main beam running through the area. 

The cost of the project was around $100,000. On the plus side, the seller is now able to market an apartment with significant improvements. “She basically got an old apartment turned into a brand new apartment because we had to gut it,” Koppel says. The takeaway is to take sagging floors seriously and fully diagnose the extent of the problem.  “It does happen with age where the floors start to sag a bit but it certainly needs to be investigated,” Gurevich says.