We are about to lay new wood floor in the entire upstairs of an old Victorian house. This seems like the perfect opportunity to acoustically (and thermally) insulate the floor to separate it from downstairs.
I was initially thinking about putting 25mm acoustic roll in-between the joists (1st floor) but I can't find any information about if 25mm will be sufficient e.g http://www.roofingsuperstore.co.uk/product/25mm-knauf-earthwool-acoustic-roll-4-x-600mm-x-200m-2400m2-pack.html
Then I thought about the idea of using 100mm loft insulation roll as its cheap but can't find out its accoustic properties. e.g http://www.wickes.co.uk/invt/109449
Should I use acoustic roll or loft roll?
What thickness should I use?
What is the cheapest option for me?
Thanks for your time!