How do you soundproof the floor of an apartment? Urgent!?

Question

My floor in a purpose-built block consists of a concrete base to which long parallel lengths of approx. 5cm x 3cm wood have been screwed about 30cm apart. Floorboards are screwed to these lengths at right-angles, leaving a series of long voids across the whole floor.

When we recently got rid of the carpet and its underlay and laid on top of the floorboards a layer of best quality wood-floor insulation with a 2cm-thick oak floor on top of that, neighbours underneath (and above!) started complaining about the noise and have continued ever since.

It seems to me that the voids between the concrete floor and the floorboards are now acting as sounding boards. What would you use to fill up these voids, and before screwing back the floorboards, what about adding a very thin layer of insulation to the top of each long parallel length of wood first?

Or maybe there's another option entirely that doesn't involve taking everything up? Drilling holes and pumping something in? Trouble with that is, there are pipes and cables underneath. I don't want to replace the carpet, though.

Answer 1

Look for rubber soundproofing flooring pads, they're quite heavy to lift, but the are designed for soundproofing floors, they have a dense foam on the back, simply lay them down on the floor, and lay your carpet on top of it, downstairs won't even know you're there! and it's great insulation if your place is cold as well, the only downside to this is that you need to shave the bottom of the doors to make up for the extra height, it's only about 3/4 -1 inch thick, but if it works, it's worth it. explain to the neighbours what you're doing and they may even help you do it.

Answer 2

Sound is carried in two ways: by transmission - ie through solid objects or through a liquid by vibration, or by the vibration of air. To sound proof a space you must prevent both happening. If you wish to 'pump' something in you could use expanding polyurethane foam (crazy foam) the kind used to fill holes in walls where pipework goes through. This will however be expensive and unreliable as you will never be sure it fills all the gaps. The only way to sound proof between your flat and the one bellow is to lift the floor, inter lay an insulator such as plastezote or evozote between your joists leaving no gaps. Then lay an insulating veneer on top of your joists such as the sheet sold to go under laminate flooring. Following this relay your floor. This will help but not stop sound transmission between you and those bellow.

As far as those above go you will either have to do the same with their floor or put a suspended ceiling in your flat, either way, it's a pain.

The very best way to solve the problem and probably the cheapest is to put thin felt (or even carpet) feet on the bottom of your chairs and other furniture which gets moved - this will stop the clank and scrape. Next buy yourself some slippers. The complete remedy costing less than £30 and the only real viable cure if you don't want carpet or rugs back. Good luck.

Answer 3

You said when you got rid of carpet you laid down best quality wood floor insulation with 2cm. thick oak floor on top. Sounds like you put thin styro type underlay that is used for laminate flooring. Anything 2cm. must be laminate. This is not real oak. If you have voids in subfloor put plywood down first for your type of flooring. Holes could be cut in floorboards to allow for blow in cellulose insulation,then you might be ok with out plywood.

Answer 4

Go back to a carpet. It is the only way.

Wooden flooring should be banned apart from the ground floor purely due to the noise annoying the neighbours.

Answer 5

You already have the framing for the wooden flooring, all you need to do is install rockwool insulation between the wooden floor board and the concrete slab. This will definitely improve your soundproofing.

Answer 6

I'd go back to carpeting and make sure you get a good thick pad.

Answer 7

I had the same problem with a neighbour when i lived in a flat.

Wooden flooring should be banned if you live above ground level in a flat!

Answer 8

talk to your neighbors, talk to your landlord, work something out.