My approach to Sound Proofing Timber Floor

radooo

The upper floor in my house is quite bouncy and very squeaky and needs the attention.

The house is approximately 3-year old; however the builder is quite difficult to deal with and I decided to fix it myself. I have removed laminated floor and was quite surprised that apart from osb board (0.78inch) white foam sitting under laminated floor there is no single insulation material - not even rockwool or another type of mineral wool. Joists are 9x2 timber with 14 inches spacing. Image here:

Would this poor craftmanship be common with new houses? Isn't a builder required to put at least mineral wool in between joists for fire safety in new houses?

I am thinking of adding insulation in the following manner:

1. Lay isover acoustic mineral wool (thinking 100 or 150mm thick) in between joists (or would you recommend a different product / material?)

2. Lay 10mm rubber acoustic mat on osb board. Thinking of cutting stripes from this rubber material as well and placing them in between osb boards as there seems to be friction between them and creating a lot of noise as these are not properly laid on timber floor. Is using rubber mat a good idea for soundproofing floors? The other alternative of rubber mat is on amazon but not as thick and it is also more pricey. Additionally, wouldn't it be a better idea to lay the rubber in between the joists and the osb board?

3. On top of rubber I want to add 5mm Selitac underlay which I hope this will help further improve both airborne and impact sound barrier. Is it a good idea?

4. Finish with the existing laminated floor.

What is your experience, would the above approach work or do you have a better suggestion on the best practices when it comes to soundproofing upper floors in the house with a moderate budget?

Thank you for your suggestion in advance.

Calahonda52

Fire regs are met by the plaster board

mineral wool is not a fire barrier.

Part B here:
http://www.environ.ie/housing/building-standards/tgd-part-d-materials-and-workmanship/technical-guidance-documents

On the rest IMO, insulating between the joists will not do much for sound as it is carried by air as well as by transmission

Re the squeaking, you need to screw the osb down.

Dudda

Take up the OSB. Put 100mm insulation between the joists as you described. Lay GypFloor Silent on top of the joists. That's a Gypframe SIF1 Floor Channel fixed to the joists with a Gypframe SIF2 Floor Channel to the perimeter. Place Gyproc Plank between the joists resting on the SIF1 channel. Put OSB back on top but screwing into the channel not the joist. I've used this system in places where noise control is critical like libraries, a theatre and will soon have it in my own house.

The GypFloor system is a sponge channel that stops the osb or timber boards getting fixed directly to the timber joists. If you were to just put matting between the OSB and joists any nails or screws connecting the two through the matting would just transfer the sound. If you wanted a high quality underlay in addition the best I've come across and used is the 'SoundService Quietfloor Plus' but it is expensive and you shouldn't need it with the above.

Calahonda52

Interesting solution the Gypframe: what over all thickness is it, OP may need to trim doors and it may require a step up from landing....

Retrofitting the insulation with cables, noggins, pipes, light fittings, etc etc is not going to be as effective as you might expect / think, hence my suggestion that it wont add much to the party, to work properly it ideally has to sit fully on the plaster board and be a snug, uncompressed fit between the joists.
The idea behind it is to try and reduce the drum effect of the PB, as well as be 100% airtight, which will be hard to do with lights
https://en.wikipedia.org/wiki/Acoustic_transmission

Dudda

Calahonda52 wrote: »

Interesting solution the Gypframe: what over all thickness is it, OP may need to trim doors and it may require a step up from landing....

Retrofitting the insulation with cables, noggins, pipes, light fittings, etc etc is not going to be as effective as you might expect / think, hence my suggestion that it wont add much to the party, to work properly it ideally has to sit fully on the plaster board and be a snug, uncompressed fit between the joists.
The idea behind it is to try and reduce the drum effect of the PB, as well as be 100% airtight, which will be hard to do with lights
https://en.wikipedia.org/wiki/Acoustic_transmission

It's 12mm higher I think. You can lose it in the carpet or small trim at the door.

True the insulation won't add much but the gyproc plank laid across the top will. It's additional heavy 15mm plasterboard and with the plasterboard to the ceiling below creates a sandwich for the insulation.