insulating for sound/thermal beween ground and first floor?

[Pottman]

After looking around for quite some time i'm still unsure if this is a good idea or not, or if it is, the method of installation to take.

I've had all the boards removed upstairs for new wiring and CH... so can get to the void.

I'm thinking about going with 50mm Slab insulation
(http://www.wickes.co.uk/General-Constructional-Insulation/General-Purpose-Insulation/invt/161197)

So the question is do I install close to the plasterboard of the ceiling below and rely on the board and the friction fit to support? or do I install close to the underside of the new floorboards that are going down, and need to support with battens or netting?

Also there seems to be a question as to how electical cables respond to being enclosed in insulation, so I assume this is best if they are run in the air space either above or below the insulation (depending on wich installation method is recommended)

Hope I've made my intentions and questions clear....

Thanks for any help

 

[Symptoms]

Pottman - why bother to apply thermal insulation between floors WITHIN a dwelling unless the space below is a 'cold' area, say like a garage? Acoustic insulation is another matter altogether.

There are two issues to be addressed: impact insulation & air-bourne insulation.

Air-bourne - voids between floor & ceiling to be filled with something like vermiculite (designed to increase the mass of the floor & cut down on sound transmission through the air in the void). The advantage of using loose fill material (vermiculite) is that it'll fill all the inaccesable places, under bracing for example, unlike slabs that have to be wrestled into positon. Remember, if the air can get in or through then so can sound so you have to combat airborne sound with the loose fill.

Impact - acoustic quilting to be laid over an existing wooden floor and a secondary 'floating' floor to be installed over the quilt, this minimised impact sound (noise of feet, etc). The impact sound has to be dealt with using acoustic quilt (underlay, pads, sheeting designed for the purpose) not loft insulation got from B&Q. Google for info & suppliers in your area.

 

[Pottman]

Symptoms, thanks for the response..

However, I had seen this
http://www.energysavingtrust.org.uk/home_improvements/home_insulation_glazing/floor_insulation

which suggests that thermal insulation between floors is a consideration for money saving? (unless they are meaning only when the bedroom in question is above a cold zone, though it doesn't explicitly say that?)

Is it not the case that thermal insulation between floors will retain the heat downstairs in the zones that are normally required to be warmer... rather than allowing it to heat the bedroooms above which usually require a lower temp?

Again, thanks for your input...

(PS I have loose fill vermiculite in the loft and the pain it causes when changing light fittings etc with it dropping all over the place is something to keep in mind!)

Mike

 

[freeflyer]

i worked as a sound engineer for years so i dabbled a bit in sound proofing...
anyway...

Its only the high frequencies which any kind of cavity insulation will stop.. high frequencies will tend to bounce around inside the material and dissipate as heat (miniscule amounts, obviously).

Low frequencies on the other hand are very very difficult to stop.. especially in a house... and given that most footstep noises are low frequency, then you have trouble.
Wood is one of the next best transmitters of sound after air... given that most of your house is made of wood touching wood, the transmission of the lower frequencies through the house is inevitable, as it will travel from your feet, then the room along the floorbards, tthe joists, and anything else thats connected together. This in turn will resonate and reproduce the sound across any large flat surface elsewhere in the house... effectively your walls are acting like a big speaker.

If you can lay a sound absortion layer between the floorboards and the joists (effectively sepearating the joists and floorboard) , then this will cut down the low frequencies massively, although i dont know how practical this would be. I guess the post above would do the same thing.

Of course... i was a sound techie.. not a builder.. so it may not be applicable at all to houses !! but sound is sound.. if it was me i'd oncentrate on the floor deadening properties rather than the cavity deadening.