I am remodeling the first floor apartment in my multi-family house in NYC. The ceiling in the kitchen is 9’3” high. I am dropping the ceiling to 8’2” to accommodate air conditioning ducts. I plan to put in fiberglass bats between the ceiling beams to insulate the ceiling for sound from the above apartment. My question is, do I need to install a layer of sheetrock directly to the ceiling beams and below the insulation and another to form my new dropped ceiling, or can I simply put up one ceiling on the lower part? Also, because I’m planning to use recessed LED lights in the kitchen, does the space above the dropped ceiling have to be vented?
Thanks in advance for your help.
Replies
There are an awful lot of variables there, in particular fire code issues. You should not trust any info you get on the internet for this -- you need to actually consult someone who both knows NYC code and can physically look at your setup.
But I'm gonna bet that you need to restore the existing ceiling to be "fire tight", and you may also need to install fire blocks to cut the enclosed area into halves or quarters.
I think that makes sense too - not only to make it "Fire Tight", but "Sound Tight" as well. Fight your sound and fire barrier battle at the 9' level. Make sure everything is properly taped and sealed with the correct products. Use at least 2 layers of 5/8" drywall with green glue between layers and accustical caulk at the corners and seams.
Create a seperate isolated plane at the 8' level for your lights and wiring. DON'T JOIN THE TWO, or you will get a direct pathway for sound to communicate through.
But don't forget to put fire shutters in the ducts if/where they pass through the old ceiling.