Condo soundproofing, especially floor to ceiling soundproofing is by far the biggest soundproofing issue we deal with here at Soundproofing America, Inc. There are many ways to deal with the Impact and the airborne sounds from a neighbor above, so there is hope for the downstairs neighbors.
The most effective method for soundproofing the ceiling in a lower unit is to actually remove the existing drywall ceiling and install a sound insulation into the joist (beams) of the floor ceiling assembly. Good insulations are Rockwool and a cotton insulation called Ultra Touch. These type insulations provide a measure of sound absorption and they also help to dampen the joist structure above. The next step would be to install a layer of a product called mass loaded vinyl. Mass loaded vinyl or MLV as it is known by is a high grade vinyl that is impregnated with barium salts and silica (sand) to give it mass. MLV is a smooth vinyl that is designed to emulate lead sheeting but without all of the hazards of lead.
The MLV will be stapled or nailed directly to the bottom facing of the floor joists, much like a membrane across the entire ceiling. You will overlap the seams by at least 1” and it is recommended that the overlap be caulked with acoustical caulk and then taped with a seam sealer tape.
Once the MLV is installed and sealed, you should experience a good amount of soundproofing from the floor above. If you feel that this enough soundproofing then I suggest putting up a layer of 5/8” fire code drywall directly over top of the MLV membrane. Remember to NOT install recessed lighting in a soundproofed ceiling.
Now if this system does not block enough of the impact noise, then you will not need to put up the drywall at this point, you will need to install a floated ceiling using sound clips and furring channels. This can be labor intensive so be mindful of the hours a contractor is spending on this installation. Floating a ceiling can be done 2 ways; one is with resilient channels and the other with sound clips and furring channel. Resilient channels are old school soundproofing and do not work that well. The chance of installation error is greatly increased when using (RC) resilient channels.
The preferred way is to use sound clips and furring channels to float your ceiling. Basically the sound clips are a 3” long X 1” wide clips that are designed to hold a metal furring channel which the new drywall will be screwed directly into. The sound clips have a rubber insulator that isolates the clips and everything attached to the clip from the joist structure above. I know this sound a bit confusing, but bear with me.
The sound clips will screw directly through the MLV membrane into the face of the joist. You will position the sound clips every 4 square ft. Once the clips are screwed to the joists, they will be fitted with a 25 gauge metal furring channel which is the interface between the sound clips and the new layer of drywall that will be screwed into the metal furring channel. Once the furring strips are mounted into the clips you would simply screw the drywall directly unto the channels with ordinary drywall screws. The clips and furring channels can hold 36-40 pounds per clip. Keep in mind that as you install the drywall ceiling it is essential to leave a 1/4” gap around the entire perimeter of the ceiling, where the floated ceiling does not touch the adjoining walls. This gap will be filled with a combination of backer rod and acoustical caulk giving the ceiling a finished appearance while maintain the floating ability of the ceiling assembly itself.