Sometimes a separating floor has to be upgraded to comply with Part E Building Regulations for control of noise penetration when access to the ceiling below is not possible.  Normally this is with change of use projects when the first floor of a property is changing from say an office to residential and the premises below are remaining commercial.  In these cases, access is only possible from above the floor for the installation of any sound insulating products.

Normally, to comply with Part E, a separating floor has to have sound insulation applied to the ceiling, between the joists and onto the floor itself.  Sound insulation that has been properly installed into these areas will comfortably pass both the impact and airborne noise limits defined by Part E.  Unless there is flanking noise around the floor down lightweight walls.  Flanking noise is usually only a problem with buildings incorporating cavity structural walls.  Buildings with solid structural walls do not normally present a problem.

Now separating floors that have to be sound insulated from above will not normally fully comply with Part E because it has not been possible to work on the ceiling.  In these cases, Building Control will normally accept that the sound insulating work possible is the best sound insulation that can be installed and will sign the contract off as accepted.  The following details will describe what can be done in these circumstances and you can be assured, it will be very difficult to improve on this.

  1. First remove the skirting boards and floorboards.
  2. Fix chicken wire to the bottom of the joists to contain the AMW100 acoustic mineral wool.  This action will also give the floor the required 1 hour fire protection from below.
  3. Install 100mm of AMW100 acoustic mineral wool between the joists ensuring it is a loose fit.  Cut the insulation to fit and use the offcuts as well so there is no wastage.
  4. Screw 19mm high density QuietBoard acoustic flooring to the top of the joists ensuring the floor does not squeak when walked on.
  5. Unroll 10mm R10 resilient rubber impact absorbing insulation over the entire floor wall to wall with the joints butted tightly together.  It is not necessary to lap this insulation up the walls.
  6. Install another layer of 19mm QuietBoard on top of the R10 but this time with the joints glued.  DO NOT use any mechanical fixings.  When laying this layer, ensure that an expansion gap of approximately 5mm is maintained all around the edges where the flooring meets the wall.
  7. Seal the expansion gap with flexible Acoustic Sealant.
  8. Now the skirting boards can be fixed but it is important these do not touch the new floor so ensure there is a gap of about 1mm between the skirting and the floor.

Click HERE for more information and access to more installation instructions.

Now the job is completed and you have done all that is possible to meet Part E.  If ever it is possible in the future to carry out the necessary work on the ceiling below it will be worthwhile.

Written by Stephen Young

© Sound Service (Oxford) Ltd. 2004


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