Suz wrote:

Oh why is nothing ever simple?

The idea is to have real strudy floor to minimise any bend and noise
transference. The longest one will be in the roofspace and as the kids will
be there I want to reduce the elephantitis noise from above.

As the others said, the best way to do this is to de-couple your ceiling
from their floor. Insulation between helps, as does choosing a really
good carpet underlay for the new floor.

Have a look at what I did for my loft:

http://www.internode.co.uk/loft/floor.htm

The last couple of piccies show it best. I still had a small amount of
coupling between floor and ceiling since I needed to provide the lateral
bracing that used to be archived with tie beams. But even with this
there is noticeably less noise transmitted between 2nd and 1st floors
than there is between 1st and ground floors for example.

(and in spite of first-born in the room above being small and looking
rather dainty, seems to move with the acoustic aplomb of a small heard
of buffalo... nice thing is you can hardly hear it through the ceiling)

Another way to increase floor stiffness is with herringbone straps
across the joists either in the mid span or at 1/3 and 2/3 span. These
can either be cut from timber and done in the traditional way, or using
modern galvanised ones. Either way they just nail in place.

--
Cheers,

John.

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