Soundproofing a floor to Part E Standard #3

A previous Blog was an introduction to floor soundproofing and mainly talked about flanking noise and how to deal with it.  That Blog also referred to upgrading the soundproofing of a separating floor in flats to comply with the Building Regulations for the control of noise through floors.  These regulations are contained within a document called Part E Resistance to the Passage of Sound.  For a lot of new build and change of use when a building has been converted into flats, the floors have to be tested to prove compliance.  But in the case of upgrading an existing separating floor no testing is required.  This is because there is no legal obligation to bring an existing floor within a flat to comply with current regulations for noise control.  Having said that there are still many flat owners that would like to upgrade their floors and if they have the co-operation of their neighbour beneath, then it should be possible to upgrade to a good level of soundproofing.

First off, if there is a lathe and plaster ceiling attached to the ceiling below whatever you do not remove it!  Lathe and plaster ceilings are better than the plasterboard replacements often used instead.  What should be done is simply screw up another layer of 15mm high density Acoustic Plasterboard that will add mass and secure the plaster from detaching from the lathes as sometimes happens when it has been up there for a long time.

If it is simply a plasterboard ceiling then this can be removed and replaced with 30mm (2 x 15mm) of Acoustic Plasterboard decoupled from the underside of the joists with 15mm deep Resilient Bars.  Inset ceiling lights should be avoided because these will let noise through just as easily as leaving a hole in the ceiling.  All lighting should be surface mounted with holes for wiring sealed with Acoustic Sealant.  More information our Resilient Bar system including installation instructions can be viewed on our web site.  This work on the ceiling is all that is required from below.  The rest of the soundproofing can now be installed from above.  For flat owners that do not have the co-operation of neighbours above, carrying out the work just described will reduce noise through the floor from above and if you can also install 100mm of Acoustic Mineral Wool (AMW100) as a loose fit to sit on top of the Resilient Bars, it will be difficult to improve on the soundproofing carried out from below.

Now we can go to the work that can be carried out from above and the same applies here.  If you do not have the co-operation of the neighbour beneath, the following soundproofing work will be the best you can achieve and certainly worthwhile.

First of all remove the skirting boards and lift the floorboards to expose the joists beneath then insert as a loose fit 100mm of AMW100 Acoustic Mineral Wool that is a Rockwool type product but produced to s specific density to give maximum sound absorption.  Now if the floorboards are in good condition, refit them with screws strategically placed so the boards don’t squeak when walked on.  Ensure that any gaps around the perimeter of the floor are sealed with Acoustic Sealant.  If the floorboards are not fit for re-use, replace them with 18mm QuietBoard, a high density tongued and grooved acoustic floorboard.  Once the floor is laid and sealed, overlay with 2mm of SBM5 Soundproofing Mat loose laid wall to wall with the joints tight together.  Once that s down then overlay with 10mm of R10, a recycled rubber resilient insulation for supporting a floating floor.  This has to be laid across the entire floor with the joints tightly butted.  Once this is down, a floating floor of QuietBoard can be laid on top but this time with a 5mm gap around the edges that can be sealed with Acoustic Sealant.  All that now remains is to refit the skirting boards so as to be just clear of the floating floor.  About 1mm is sufficient and this gap does not require sealing.

That’s it.  Job done and now you can get on with fitting the floor covering and for best results, make it carpet on top of a felt underlay.

All of the above soundproofing can be carried out as a DIY exercise by anyone used to handling small tools and full installation instructions to soundproof a floor can be viewed on our web site www.keepitquiet.co.uk