MayrCh
2019-12-28 21:04:53
- #1
Sound insulation according to DIN 4009, Supplement 1 was exceeded.
I guess DIN 4109 is meant. Supplement 1 must be strictly complied with. If not, it is automatically a defect. However, it is hardly possible to build so poorly anymore.
The developer claims to have built according to current technical rules.
Do you have that in writing? If yes, take it to a specialist lawyer. There are court rulings almost 15 years old that argue that 4109 was not (not even at the year of publication 1989) considered a recognized state of the art, because it was (even back then) absolutely inferior.
Your expert should have dealt with that already, if he knows his stuff.
The measurement of the low-frequency areas (impact sound) resulted in a value over 70 dB!!!!!!!
What arrives at the microphone as sound pressure level during impact sound measurement is initially completely irrelevant. The standard tapping machine makes a tremendous racket; in new buildings with 22 cm concrete slab, floating screed, and hard floor covering, I achieved sound pressure levels between 75 and 80 dB in the receiving room one floor below with the common standard tapping machine, and significantly more below the 63 Hz third octave.
What is important and relevant is exclusively the calculated impact sound insulation index. Your expert should have mentioned that somewhere as well.