Cầu tồn tại trong tất cả các tòa nhà và tầm quan trọng của nó trong việc xác định cách âm rõ ràng (cảm nhận của những người cư ngụ) phụ thuộc vào các chi tiết xây dựng của các bức tường, sàn nhà và các nút giao của nó. | Page 22 of 103 Summary - Vertical Flanking in Typical Constructions For the case of two apartments vertically separated by a floor ceiling assembly the Apparent-STC between the two occupancies is systematically less than the STC for direct transmission through the separating floor. There are three main issues 1. The main flanking path is consistently from the subfloor of the room above to the walls of the room below or vice versa if the subfloor is a layer of oriented strand board OSB or of plywood directly fastened to the top of the floor joists. 2. Some changes in the wall below can significantly reduce transmission via a specific wall surface. Adding a second layer of gypsum board reduces flanking. Mounting gypsum board on resilient channels should reduce flanking to insignificance for most practical floor assemblies. 3. Reduction of Apparent-STC by flanking depends on the flanking transmission via a walls of the room below. As discussed in the detailed report 1 the estimates in this section should be applied only for cases where wall and floor details are within the range of the tested specimens links to specifications are in section on Changes to Control Horizontal Flanking This Guide ignores the vertical sound transmission between stories within a single occupancy where the gypsum board ceiling is screwed directly to the floor joists called row housing in later sections IRC RR-219 Guide for Sound Insulation in Wood Frame Construction March 2006 Page 23 of 103 Changes to Control Vertical Flanking between Apartments One apartment above another Airborne Sound Source For the case of two apartments vertically separated by a floor ceiling assembly vertical transmission 1. Changes to control flanking must be focused on the elements of the dominant flanking path. 2. The two surfaces that can be modified to reduce flanking transmission are the walls in the room below and the floor surface in the room above. 3. Effects of some common changes are presented in this .
