Floating Floor Sound Insulation?

A good freind of mine has just bought a 1st floor flat in an old house conversion. Baisicly I had the floor up to do some electrical work and the builders/ developer has insulated the floating timber floor with sand and plastic sheeting. On the grnd flr the tennants works shifts so my freind being a nice guy wants to sound proof his flat as much as possible. Ive read about R10 insulation but this is a major job so i'm wondering if there's a certain type of rock wall I can lay between the joist? If we use R10 then it's a case of pulling the place to bit's rather then lifting the floor boards up. Any advice would be welcome.

Gingernuts wrote: A good freind of mine has just bought a 1st floor flat in an old house conversion. Baisicly I had the floor up to do some electrical work and the builders/ developer has insulated the floating timber floor with sand and plastic sheeting. On the grnd flr the tennants works shifts so my freind being a nice guy wants to sound proof his flat as much as possible. Ive read about R10 insulation but this is a major job so i'm wondering if there's a certain type of rock wall I can lay between the joist? If we use R10 then it's a case of pulling the place to bit's rather then lifting the floor boards up. Any advice would be welcome.

how do you mean "insulated with sand and plastic?"

on a 1st floor?

a typical floating floor would be t&g floorboards ontop of closed cell insulation

do you mean suspended floor? because that's generally what first floor with joists are

thing is, sound travels through the structure, not just directly the floor composition

it really depends what freq your looking to reduce

i have a load of papers and info on this sort of thing which might help, so if you can be more specific...

The original floor has 2 by 4 joist on top with plastic sheeting laid between the 'new' joist and a thin layer of sharp sand as insulation. The new floor boards have been fitted ontop of the 'new' joists. It's a bodge baisicly, they've tried to create an air void and isolate any sound with the sand. It's for day to day noise not studio related ect.

www.soundservice.co.uk/robust-de ... adles.html

Ben I´ve done some floors with stuff that look like this , I´l say they do work they really take-off alot of the sound that
the guys down stairs would hear , Saul you should have some info on these kind of things , don´t you ?
not cheap thu.

Francis