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 stands for Sound Transmission Class. Basically, STC ratings are an established way to average how much sound is stopped by something. STC ratings are used for windows, doors, walls and most building materials. For windows, STC ratings range from 18 to 38.STC ratings are the ONLY way to accurately compare various noise reduction products.n STC rating is an instrument measurement of how much noise is stopped. The STC ratings allow accurate âapple to appleâ comparisons. The STC rating is the average amount of noise stopped at 18 different frequencies, measured in decibels.