We are looking for the highest, most cost effective STC that we can
incorporate in renovation of 30 multiFamily, 4 unit Gut Renovation
projects we have up coming. We would like to find the best system -
relative to cost vs performance out there for High STC ratings between
units sharing ceiling/floor as well as units sharing commom walls.
Wall framing is True 2x4 (not 1.5"x3.5") on common walls and we are
not sure on the sizing of the ceiling/Floor joices  at this point. You
could assume 2x10" or 2x12". And they will have 1x10" planking
(typicall of old victorians built early 1900s)
We can assume that at some point there is a deminishing return on STC
inprovement vs costs. The more money added to a particular shared wall
system or shared Ceiling/Floor system - once a certain STC is
acheived, the less the return for adding adding additional layers of
sheet rock, insultation, resilent channel etc. #3What is a good cut
off STC point where condo owners do not generaly complain about
hearing noise from another unit?