There can be many reasons for sound insulation failures such as air leakage paths, flanking transmission, inappropriate specification and poor workmanship.
When trying to minimise sound between two spaces it is important to ensure air paths in the vicinity of the sound reducing element are properly detailed, these include doorsets, glazing, suspended ceiling cavities, ductwork, etc. All of these will have a significant effect on the performance of the element. For these reasons it is unlikely that figures quoted from laboratory test conditions will be achieved in practice, however good detailing at the design stage will minimise this effect and optimise the overall levels of acoustic performance achieved.
Small openings such as gaps, cracks or holes will conduct airborne sounds and can significantly reduce the sound insulation of a construction. For optimum sound insulation a construction must be airtight. Within masonry constructions most gaps can be sealed using Gyproc Soundcoat Plus, Thistle plaster or Gyproc jointing compounds. Gaps are also common at the base of partitions, particularly when boards are lifted tight to the ceiling. Small gaps or air paths can be sealed with our Gyproc Sealant.
Please refer to White Book Chapter 02 Section 01 Page 08 for more details.