Can we use this old insulation between floors for sound proofing?

[u587162]

We have lots of this (see pic below) old polystyrene insulation which we have removed from our loft as part of a house remodel.

Rather than just throw it away I thought it would make good sound insulation properties between floors (placed between the floor joists).

Are there any issues with this that I should consider? I recall many people say never use polystyrene ceiling tiles due to fire / smoldering risk but would my proposal be ok because it's between floors?

 

[Burnerman]

Its good insulation but lethal if it does burn.....nasties including carbon monoxide and phosgene I believe.
Personally I'd go for inert block insulation or rockwool equivalent.
John

 

[ey143]

Thanks.

Would rockwool offer better sound insulation do you think? Can you point me to a good example product?

 

[Burnerman]

Consider Wickes acoustic insulation 161189 or general purpose insulation 161236.
John

 

[DIYWell]

I'd agree with the rockwool route. Unless you're in a rush, wait until one of the big sheds has a 3 for 2 offer which is what I did.

One thing to think about, and it's the bain of acoustic engineers, is sound bleed through at wall/floor joints. Might be worth over stuffing to compensate.

 

[ey143]

I'd agree with the rockwool route. Unless you're in a rush, wait until one of the big sheds has a 3 for 2 offer which is what I did.

One thing to think about, and it's the bain of acoustic engineers, is sound bleed through at wall/floor joints. Might be worth over stuffing to compensate.

Sorry I didn't understand you msg. You mention sheds because you think it would be good to use as insulation in an outbuilding?
Or then stick with rockwool and use these too???

 

[DIYWell]

"Big sheds" ... the likes of B&Q, Wickes, Homebase etc etc

 

[SmileyDan]

If you don't want it, sell it, because someone will find that perfectly useful as thermal insulation.

 

[ey143]

Oh ok. Builders talk

Is there a limit to how much of the Rockwool should be put in before it becomes a hazard of some sort?

Also what's the difference between the ordinary Rockwool and the acoustic one?

 

[ey143]

If you don't want it, sell it, because someone will find that perfectly useful as thermal insulation.

I tried giving it away for free on Freecycle - nobody replied! Suggestions for price if I do manage to sell it?

 

[JohnD]

It's worth about half a penny per tonne. Take it to the tip.

 

[SmileyDan]

Well I'd have it! I'd give you £20-30 for everything in the picture. A lot cheaper than buying it from a builders merchant. Assume we're talking at least EPS70 here.

 

[ey143]

Well I'd have it! I'd give you £20-30 for everything in the picture. A lot cheaper than buying it from a builders merchant. Assume we're talking at least EPS70 here.

Hi

Just sent you a private msg. Not sure how I would find out if it is EPS70...whatever that means?

 

[SmileyDan]

The 70 is the grade, the compressive strength. 70 is common for undemanding loads.

 

[geraldthehamster]

"Big sheds" ... the likes of B&Q, Wickes, Homebase etc etc

Ought to be banned.