Ok, Jimmy.

I have looked at Part E quite carefully and can find no reference to this for existing buildings. I don't know where this came from, saying it is "muddy" is not true, the section on domestic floor acoustics is specifically about new builds.

webarchive.nationalarchives.gov.uk/20141202105407/www.planningportal.gov.uk/.../BR_PDF_AD_E_2010.pdf page numbered 66.

I suggest you ask your independent BI for the exact details he thinks are there, because if you really want noise isolation this very simple design is not the way to do it! It is also fiddly to install, needing all the floor up, or if you really want to make it tricky the ceiling down!

Have a look here www.rockwool.com/uk/advice-and-inspiration/why-stone-wool/acoustic-capabilities/, there are several useful videos.

Rockwool only seems to consider conversions to flats, which is obviously where the acoustic properties are most important.


I should point out that I have been involved in the design of quite a few sets of acoustic treatment and as these are for broadcast and performance spaces, the results have to be good and have been!

I'll give a quick rundown on the theory. I suggest the treatment of the ceiling (above) in your house for minimum noise transmission is the best solution because most of the low-frequency transmission through a timber joist floor is via the joists, not through the space between. Higher frequencies do travel through the air space but one of the important points for attenuation is that the absorber is mechanically lossy (to reduce transmitted energy and turn it to heat) and obstructs as much of the path as possible, to ensure the air movement causes mechanical loss. This is why acoustic products are dense, non-reflective as far as possible, and very mechanically lossy. This is not true of thermal insulation where just keeping "trapped" air fairly still is all that is needed for efficiency so the fibres can be much less dense or constrained. Coupling to the air makes no difference thermally. Two layers of plasterboard are heavy and stiff enough to work as membrane absorbers for any low frequencies passed through the acoustic absorber panels from the movement of the entire floor structure from bass music, or jumping about. Note that the attenuation you are likely to achieve is not perfect, but may be of the order of 30dB if you do a good job.


I hope that description, at least, will give you a bit of traction with the BI and perhaps focus your thoughts. It will greatly decrease transmission upwards and also reduce reverberation in the downstairs room.


With no insulation to worry about in the floors, the job will be simple and quick, and may well pay for the materials for the ceiling treatment in reduced electrician costs, so probably a win-win situation. Two persons can easily treat a ceiling although the work is quite heavy, sheets of high-density plasterboard, but a couple of the prop gadgets help greatly to hold and position them. You will need some long drywall screws and an electric screwdriver! The slabs will not need many fixings as they will be clamped between the ceiling and new boards, you will need very tight joints and you might decide to glue them to the ceiling for convenience, but screws too will work well.


I look forward to the electrical notes.


Regards

David

Ok, Jimmy.

I have looked at Part E quite carefully and can find no reference to this for existing buildings. I don't know where this came from, saying it is "muddy" is not true, the section on domestic floor acoustics is specifically about new builds.

webarchive.nationalarchives.gov.uk/20141202105407/www.planningportal.gov.uk/.../BR_PDF_AD_E_2010.pdf page numbered 66.

I suggest you ask your independent BI for the exact details he thinks are there, because if you really want noise isolation this very simple design is not the way to do it! It is also fiddly to install, needing all the floor up, or if you really want to make it tricky the ceiling down!

Have a look here www.rockwool.com/uk/advice-and-inspiration/why-stone-wool/acoustic-capabilities/, there are several useful videos.

Rockwool only seems to consider conversions to flats, which is obviously where the acoustic properties are most important.


I should point out that I have been involved in the design of quite a few sets of acoustic treatment and as these are for broadcast and performance spaces, the results have to be good and have been!

I'll give a quick rundown on the theory. I suggest the treatment of the ceiling (above) in your house for minimum noise transmission is the best solution because most of the low-frequency transmission through a timber joist floor is via the joists, not through the space between. Higher frequencies do travel through the air space but one of the important points for attenuation is that the absorber is mechanically lossy (to reduce transmitted energy and turn it to heat) and obstructs as much of the path as possible, to ensure the air movement causes mechanical loss. This is why acoustic products are dense, non-reflective as far as possible, and very mechanically lossy. This is not true of thermal insulation where just keeping "trapped" air fairly still is all that is needed for efficiency so the fibres can be much less dense or constrained. Coupling to the air makes no difference thermally. Two layers of plasterboard are heavy and stiff enough to work as membrane absorbers for any low frequencies passed through the acoustic absorber panels from the movement of the entire floor structure from bass music, or jumping about. Note that the attenuation you are likely to achieve is not perfect, but may be of the order of 30dB if you do a good job.


I hope that description, at least, will give you a bit of traction with the BI and perhaps focus your thoughts. It will greatly decrease transmission upwards and also reduce reverberation in the downstairs room.


With no insulation to worry about in the floors, the job will be simple and quick, and may well pay for the materials for the ceiling treatment in reduced electrician costs, so probably a win-win situation. Two persons can easily treat a ceiling although the work is quite heavy, sheets of high-density plasterboard, but a couple of the prop gadgets help greatly to hold and position them. You will need some long drywall screws and an electric screwdriver! The slabs will not need many fixings as they will be clamped between the ceiling and new boards, you will need very tight joints and you might decide to glue them to the ceiling for convenience, but screws too will work well.


I look forward to the electrical notes.


Regards

David