Ive ended up with surplus EPS insulation - 25mm thick and now need to buy some soundproofing to fill stud work walls and first floor ceiling.  Can I use up the EPS as sound proofing layer (even a double layer) instead?

47 minutes ago, cbk said:

Ive ended up with surplus EPS insulation - 25mm thick and now need to buy some soundproofing to fill stud work walls and first floor ceiling.  Can I use up the EPS as sound proofing layer (even a double layer) instead?

The labour from cutting and fitting ( effectively ) will be far beyond the cost saving, as you’ll have lots of difficult spaces to access / fill. 
Sell it off and buy proper acoustic wool / batts afaic. 
 

https://soundproofexpert.com/polystyrene/

EPS (along other rigid cellular plastic foams) has no acoustic properties - thermal yes, acoustic no. Acoustic products either have large mass or open cell structure (to absorb sound energy). Foams are all very lightweight and have a closed cell structure - just what you don't need!!

 

The website linked above is just so wrong. Expert????????

 

Mineral wool is the best option for stud walls (with plasterboard both sides).

If you have a cold attic bung it in there instead.

14 hours ago, ADLIan said:

EPS (along other rigid cellular plastic foams) has no acoustic properties - thermal yes, acoustic no. Acoustic products either have large mass or open cell structure (to absorb sound energy). Foams are all very lightweight and have a closed cell structure - just what you don't need!!

 

The website linked above is just so wrong. Expert????????

 

Mineral wool is the best option for stud walls (with plasterboard both sides).

I actually convinced myself that the link was incorrect, but when you see prestige TF ( passivehaus rated ) companies using EPS beads, and raving about the results, then you start to reconsider your own knowledge. 
Criticism accepted, and I’m very happy to be corrected.

 

I was actually going to respond with my opinion of EPS and PIR being quite acoustically ‘transparent’, wish I had now. A lot of PIR SIPS type roofs are very noisy in the rain / hail etc, so am happy to change what I said, as this is a rolling thread on a public forum, where members reside here free of charge. Please take what I say with a pinch of salt folks, I’m only human.

Expert? Just a member on here, same as everyone else, and here to pick up info and learn on the way ( whilst sharing stuff where I would consider myself well-versed ). 
Wings clipped!!

 

10 hours ago, Iceverge said:

If you have a cold attic bung it in there instead.

defo better to use it up elsewhere for thermal insulation. 

Hi Nick - unclip those wings and fly!! My 'expert' jibe was directed to the website you linked too and certainly not a personal dig.