Insulate sound between wooden beams?

Hello,

I would like to soundproof an open wooden beam ceiling. For this, I thought about laying a layer of wood over the wooden beams, 20-25mm thick, then placing a film on it for drip protection, then laying beams on top again with impact sound insulation attached underneath. I would now like to dimension these beams as recommended to enable soundproofing. For 4cm, I would fill the spaces in between with sand. On top of everything, I would then lay chipboard or OSB again, and on that, soundproofing once more, and then floorboards, all decoupled from the walls.

Do you have any experience with this? Which materials would you use for the soundproofing? How would you transport the sand? Can it be blown in similarly to sandblasting? It would be quite a lot of work to carry all the sacks up there.....!
Does it help already to nail the first layer of floorboards instead of screwing them? Does it also make sense to put strips of impact sound insulation underneath them? It would probably be better not to have a fixed connection since the sand will already make it heavy enough. Maybe someone has experience with this.

Saludos
Bampa

You also have to first consider how much load you are allowed to apply. Old wooden beam ceilings are not designed for high loads. That’s where I would start and then think further. Your construction sounds like a lot of load to me.

Hello,

yes, the load is still manageable, the calculation was designed for a 20cm concrete slab, now we would switch to wood because concrete at the location where we wanted to build would have been too costly, crane etc.
Therefore, I assume it would probably fit.... the question is, what makes sense? Or is it common?

Old or new building? For soundproofing, mass helps the most, i.e. sand or gravel, but 4 cm is too little. At least gravel can be transported with a concrete pump (e.g. on flat roofs) otherwise carry it up.

That will be a new building on an old cellar. How many cm would be good?

This will be a new construction on an old cellar. How many cm would be good?

I would not make a wooden beam ceiling on an old cellar. 10 cm of gravel would be good