Technical Booklet G Resistance to the Passage of Sound·Page 122·B3.13
Flanking laboratory: indicative airborne sound insulation values
When a test construction achieves at least 49 dB DnT,w + Ctr in a flanking laboratory, it indicates the same construction may achieve at least 45 dB DnT,w + Ctr when built in the field.
When a test construction has airborne sound insulation of at least 49 dB DnT,w + Ctr when measured in a flanking laboratory using the procedure given in Appendix B: B2, this can be taken as indicative that the same construction (i.e. identical in all significant details) may achieve at least 45 dB DnT,w + Ctr when built in the field (see paragraph B3.11).
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