sound insulation rockwool

t45

Hello,
Was wondering if anyone has any experience of sound insulation – i am looking to add some sound proofing materials in joist in floor/ceiling – live in flat and have been recommended rockwool brand – RW3 and RWA45 – has anyone tried fitting any of this and if so which would be better in terms of performance - ive looked into it and it all seems very technical - but on basic level, the higher the density the better the performance.....
In terms of fitting is this a job for a DIY handyperson or a specialist builder?
I expect the flooring to be brought up and the slaps fitted into joists and then floor relaid....
Any ideas of recommendation on sound proofing materials?,.....
Many thanks

t45

..has anyone tried isover products? think purchased from Jewsons.....

Furts

A less disruptive way with the ceiling would be 15mm soundblock plasterboard. Seal it in place and screw it to the joists. Seal all joints and edges, and then decorate.

It could be scimmed but this will add to the cost and the increase in mass may be minimal.

the_lunatic_is_in_my_head

We are looking at the same and I'd also be interested in thoughts/suggestions on sound proofing materials.

It seems to be the denser the better, RW3 is 60kg per cubic meter and RWA45 is 45kg, this site has it going up to 140kg:

https://www.noisestopsystems.co.uk/acoustic-insulation/50mm-dfm-acoustic-insulation

I would assume as with normal insulation there comes a point where the extra offers little benefit compared to cost.

In terms of fitting, if you can lift and refit the floors then you could install yourself, it should just be a case of cutting to size and wedging between the joists.

t45

Many thanks – ive done quite a bit of research into this and spoken with rockwool – the R3 is more expensive but offers greater density – you have to order this in pallets of 12 – there’s a website called http://www.insulation4less.co.uk/ who have also been extremely helpful – they offer free shipping over £300 –
As far as I’m aware Travis Perkins stock rockwool – they have RWA45 in store but would have to order in the R3.
I’m still unsure which to go for – i have also heard than isover (stocked in Jewson’s) is not as effective in terms of performance –
I think we will go with rockwool – either R3 or RWA45...but need to find someone to do the job!

the_lunatic_is_in_my_head

Travis are pretty good and our local will usually price match, they are the same company as Wickes so that's a good place to start checking prices but they've match independent companies on other materials as well.

If the cost isn't too much I'd go for the R3 over the RWA45.

Assuming the floors aren't too difficult to lift I'd say either a proper builder or handyman could do the job really, best to see if friends and family can recommend someone they've used before, ideally you want someone who will do a neat job and not spend too much time drinking tea!

jamesperrett

Rockwool on its own is going to do very little to stop sound passing through the ceiling - you need to add mass in the form of plasterboard or similar to reduce the sound transmission. If the problem is too much noise from the flat below then you may have to look at a different floor structure to reduce sound transmission (unless you happen to have access to the ceiling below).

Grenage

The rockwool they are talking about is in the form of compressed batts.

t45

yes it's in chunks RW3 and RWA45 - is flexible too...

Furts

t45 wrote: »

yes it's in chunks RW3 and RWA45 - is flexible too...

Just bear in mind practicalities. Many joists are at 400 centres, giving a 350 gap to put in batts. Also in this gap will be noggins, herringbone strutting, solid strutting, cables, heating and water pipes, waste pipes from baths and so on. Unless you are a meticulous, perfectionist it could all be a pointless cause, It only takes the smallest of gaps somewhere and you have left a route for sound to get through. All your efforts will be wasted.


Equally with any movement, shrinkage, and sagging and your efforts will be suspect.


Then consider if your plasterboard will take the additional weight without distortion.


That is why I was suggesting over boarding - a guaranteed job with minimal disruption,

phil24_7

If overboarding, make sure you seal around the perimeter AND between all boards with an acrylic sealant as it will stay flexible. I used AC50 from toolstation. I would then board over this with normal plasterboard and skim it as normal. I would personally use rockwool AND double board as it has worked quite successfully in the walls between bedrooms in my house.