The sound insulation classes (SSK) for interior doors are regulated in accordance with VDI 3728 and differ according to the respective assessed sound insulation value Rw,P, the test dimension of the door element in the laboratory, which is given in decibels (dB):
When using soundproof doors, it should be noted that the assessed sound insulation value Rw,P is not identical with the required value for sound insulation in the installed state (= Rw,R), which is defined in DIN 4109, for example. The tested laboratory value Rw,P is reduced in the installed state, in particular due to secondary sound paths via flanking components, material, manufacturing and installation tolerances. For simplifying purposes, the following rule therefore applies to interior doors:
Rated sound insulation value in the laboratory (Rw,P) – 5 dB = maximum sound insulation value in the installed state (Rw,R)
Example: a door element with a rated sound insulation value (Rw,P) of 37 dB can meet a required sound insulation value (Rw,R) of a maximum of 32 dB when installed.
Source: bauwion
