Often overlooked in quality commercial interior construction is the importance of sound and fire ratings. Sound caulk alone helps a gypsum wall built to the structure go from a 15 STC (Sound Transmission Class) without caulk, to a 45 STC, by preventing sound from flanking around small openings in the wall. Fire ratings have become complex. It is important to reference the UL Directory, and the product data for each type of system specified.