A Fix for Footfalls

Living in the tight confines of New York City, your chances of dealing with noise complaints between neighbors are very great — and often difficult to resolve. What happened when you recently dealt with this problem at a Park Avenue prewar co-op?

We were called in after a renovation had been done on the floor above my client’s floor. That combination of two apartments involved a gut rehab. All the walls were pulled out. In these prewar buildings, and actually in some postwars as well, the walls stack up one over the other so that there is a rigidity that’s built up in the floor. When these interior walls are removed, the floor becomes more flexible, and when it flexes, it transmits sound. First there’s a footfall, which is then transferred from the floor slab to the wall in the apartment below. If that wall is not isolated from the slab, there can be a really loud creaking sound. My client basically couldn’t sleep at night because the owner above was getting out of bed and going to his studio to work, and she would hear both the footfalls and this really loud creaking sound.

Who did the board turn to for help?

Consultants were brought in. Eventually lawyers got involved — until management finally said the shareholder above had done everything possible to mitigate any noise transfer. We brought in my client’s contractor and an acoustical consultant. 

What did you find?

We found that the ceiling track that connects to the wall in my client’s apartment had not been isolated from the slab. Six or so years ago, a track was usually fastened right to the underside of the ceiling slab and another track was fastened right to the floor slab. Then the studs were put up. This wasn’t unusual. But in current practice, an isolation pad is strongly recommended so that when the slab vibrates, the pad reduces vibrations down through the wall. It’s really important to install an isolation pad when you’re renovating your apartment because you have no control over what somebody above may do.

Were you able to correct the problem?

We opened up about a two-foot-wide strip of the ceiling adjacent to the wall. We were able to get up to the ceiling track, push the studs to the side, remove the ceiling track and install an isolation pad right above where the track was to be reinstalled. We fastened it with special isolation fasteners, and then the studs were put back up.

When we tested from the apartment above, there was a reduction in the creaking. In fact, it was almost totally gone. But we knew we would not be able to eliminate the footfalls. The shareholder above put in a 10-millimeter rubber mat and wall-to-wall carpeting. You can’t install a better sound attenuation for the slab itself. Unfortunately, footfalls are always going to be a problem.

Ethelind Coblin is a founder and the design principal at Ethelind Coblin Architect.