Methods for improving the sound insulation of existing simple wood joist floors

The sound insulation provided by simple wood joist floors is known to be inadequate when such floors separate flats. The effectiveness of various methods for improving the sound insulation of this type of floor has been investigated. The problems associated with flanking sound transmission are discussed. It was found that the most effective modification tested was capable of achieving a level of sound insulation equivalent to that obtainable with modern concrete party floors, provided that the level of flanking transmission was not excessive.