This week Soundguard Acoustics Ltd sound tested a conversion of a former dwelling into three flats in Exeter, Devon. Whilst the Approved Doc E airborne tests of the floors all passed, the impact testing failed by a small margin of 2dB in some areas – but why would that be?
Discussion with the developer determined that the joists were very uneven and therefore the acoustic overlay flooring system would not lay flat without bouncing, they had therefore fitted the skirting boards tight to the flooring to keep it in place and also there was evidence of nail holes suggesting that the floors had also been tacked in some areas. So, what has happened?
Those few tacked nails have created a sound bridging pathway from the surface of the flooring into the joists below and the perimeter skirting has created a secondary flanking path via the walls into the structure of the building. A sound test failure – damn!
The solution in this situation is to either remove all the screws, nails or fixings within the floors and refit the skirtings with isolating perimeter strips or, as we did in this situation, to keep the floor in situ and bond a rubber acoustic underlay to the flooring surface to gain the additional impact requirement to pass the test.
The moral of this story – get advice early on and follow the manufacturers guidance when fitting acoustic systems, detailing is critical!
If you need assistance in meeting the Approved Doc E building regulations for your conversion or require ADE Sound Testers then call Soundguard Acoustics Ltd on 01237 478142 or email us – we are here to help.