The author fabricated a model to represent a wall whose other side is a neighbor’s property, where nothing can be changed.
The crew installs a "mass-loaded vinyl" (MLV) membrane over stud cavities filled with sound-blocking insulation such as Roxul rock wool or QuietInsul.
All seams, including the edges, are sealed with a special tape made from the same MLV material as the membrane.
The corners are also sealed.
On ceilings, a tough cord-reinforced tape is applied on top of the regular Sound Barrier tape.
Clips and channel are used for drywall furring. The clips are fastened to the studs with screws through plastic washers.
The screws touch the studs and the washers, but not the metal of the clips, effectively decoupling the studs from the clips.
Hat channel snaps onto the clips and absorbs vibrations from the studs.
On walking surfaces, QuietWalk is installed under tile or wood flooring.
For retrofits such as the stairwell party wall shown here, crew tears off existing drywall by hand.
A recip saw is handy for making occasional cuts.
Being careful not to damage existing plumbing and wiring, the crew tears out any spray foam insulation by hand and replaces it with special acoustic rock wool fiber batts.
The Sound Barrier membrane must be carefully fitted around the ceiling beams.
Though heavy, the material cuts easily with a drywall knife.
The crew nails off the Sound Barrier.
All the seams on the membrane covering a stairwell party wall are taped off. Any holes would reduce the barrier's effectiveness.