Floor sound insulation

[Lantash]

Upstairs flat of two-story 80's building. Have problem with neigbours below who complain of excessive noise from creaking floorboards and other sources above.

Boards are indeed somewhat creaky, but no more than those of some new houses I've been in. I've done some fairly extensive work on the hallway floor, and this has drastically reduced the creaking in this area. The lounge needs the same doing, when I get time.

Anyway, my question relates to sound insulation between floors of flatted properties, and what would the norms be for sound attenuating material? This floor has a layer of loose rock-chips below it, perhaps 150mm deep. Would that normally be considered adequate? Is there anything I could do to improve its sound-reducing properties?

I get the impression the neighbours are exaggerating the problem, as I can only just hear their (loud) TV upstairs. Nevertheless as I've never been allowed to carry out any kind of decibel-meter tests I have to take their word for it.

As taking-up the lounge floor is going to involve a fair amount of work, I'd like to see if there is any way to improve the sound insulation as well as fixing the creaks. Any suggestions?

 

[Deluks]

I think as you have a seperate dwelling above theirs, then a minimum requirement for fireproofing would be in order. If their ceiling doesn't meet this then they should be responsible (I think) Unless it's rented accomodation.

Adding rockwool insulation between floors will improve soundproofing somewhat AND will have the added bonus of fireproofing. So maybe you could get them to share the cost?

Gaps in floor boards will transmit sound too, so laying 18mm chipboard or ply under the floorboards (or on top of, or in place of) will reduce sound transmission, and screwing down the entire floor, instead of just using nails will prevent squeaking.

Also look into floating the floor on neoprene rubber strips, this will absorb impact to some extent. Find a specialist supplier of rubber and get a roll of 3-5mm, lay this on the joists before fixing floor down. If you use glued t&G boards then the floor will just stay in place without any fixings, and sound won't transmit through the screws. (I'd probably still put a few screws in around the edges though)

 

[Lantash]

Thanks.

The thought crossed my mind that if the rock chips could be concreted into a solid mass, that would greatly increase their effectiveness as sound insulation! I wouldn't contemplate trying that without expert professional advice though, for obvious reasons.

Anyway, a few ideas to consider. A floating 18mm MDF floor over the existing one might be one option.