If you use those plastic insulation troughs and overlap the top one of the lower ones even if rain should sneak up past the shingles, past the builders felt it will fall on the plastic trough and be carried out past the building envelope.. 1  Reply. 2  Reply to Original. 3  Print this page. 4  Email this Message.
Double-sideband suppressed-carrier transmission. Double-sideband suppressed-carrier transmission (DSB-SC) is transmission in which frequencies produced by amplitude modulation (AM) are symmetrically spaced above and below the carrier frequency and the carrier level is reduced to the lowest practical level, ideally being completely suppressed.
STC. STC stands for sound transmission class. This is the most common rating used in North America for determining airborne sound transmission loss between 125 and 4,000 Hz. This range covers the majority of common noises we hear including speech, television, music, dogs barking, and other similar annoyances.his rating increases to STC 42-45 with steel studs. The STC rating for a basic wood structure floor/ceiling is 40-43. The STC rating for a six inch concrete sub-floor is 52-55.