Hi guys!
This is a bit of a left-field request for help.
I'm in the process of buying a new apartment,and we have just found out that the neighbour underneath is a 'user' who often comes home with friends at 4am and listens to TV/Radio loudly - yeah, I know.....what luck.
Most of the neighbours around him are kind of used to the situation as they know he had family problems etc.. and they don't live directly above him, but my aprtment will be directly above. the building itself is a solid building (1920s) with thick 30-40cm solid brick external and internal walls. I don't know how thick the floors are, but they will definately be made of concrete.
Though my instinct is to get out of the sale and lose my deposit, my architect friend has advised me that the house is a bargain and worth the money, even if there is this 'annoyance' below.
Soooooo, my question is does anyone have experinece of 'extreme' soundproofing for floors.
I've sounproofed my current house somewhat with Fonostop Duo, which worked quite well at blocking some noise from neighbours, but this may be a more extreme job. I'm thinking soundmats, MDF flooring, greenglue, vinyl or leadsheeting. Or combinations of several layed on top of the existing floors to block all rising noise.
I wanted to know if anyone has experience of what worked best in what combination.
 
Any help would be appreciated.
 

like any other soundproofing challenge you need mass and a spring.

I was able to soundproof my second floor studio years ago with a layer of homosote covered with a layer of thick drywall and a layer of 3/4" plywood. I don't remember what the STC turned out to be, but it was more than sufficient for my use, which was to avoid barking dogs and appliances from interfering with my music production.

You'll need to cover quite a bit of your floor, anything that isn't treated becomes a flanking path, and that's bad.
 
It can be done. Can't say for certain that it can be done economically in your case, but it shouldn't be a huge cost. Depending on just how much mass you are adding you may also want to check with a structural engineer to make sure you don't end up visiting your downstairs neighbor.
 
Good luck, and if you think of it please report back.

Soundproofing a floor will not be as cost-effective as soundproofing the ceiling below it. Is that even an option for you? Most acoustics will not bridge an air/surface interface, but if the building is as rigid as you say, lower frequencies are going to transmit the best throughout anyway. Floor joists are far easier to work with (from below), but if that is truly a concrete slab, it will want to resonate (if properly driven from below).
 
If the cost of soundproofing will exceed your deposit, it is very much worth considering following your gut instinct. Don't throw good money after bad.

Look into Green Glue. 

only mass soundproofs.
 
here, i'll say it again........
 
only mass soundproofs.

wst3
I was able to soundproof my second floor studio years ago with a layer of homosote covered with a layer of thick drywall and a layer of 3/4" plywood. I don't remember what the STC turned out to be, but it was more than sufficient for my use, which was to avoid barking dogs and appliances from interfering with my music production.

Thanks wst3. Did you use any special drywall? I've seen that there are different types which claim to be 'special soundproofing' drywall, but I wonder how true that is. If I just use an ordinary drywall sandwich with a layer of greenglue between, I might be able to block nearly all the sound.
 
In the last few days, my wife and I have been trying to understand just how bad this situation is by speaking to everyone who lives there. Seems the owner is a young guy (30) with serious family issues, health problems and drug problems, who is sorrounded by bad leeches. He's had an ulucky life: lost his mother a few years ago and has been abandoned by his father. It's a really ****ty situation because the building block is really nice, all the other residents are artists, dancers, musicians, teachers. All really good people. It's just this one guy, who isn't evil, just unlucky and unpredictable.
If we can manage to make it work somehow, there is the chance that he will be moved into an institute, or not come back from hospital one day.

mettelus Is that even an option for you? Most acoustics will not bridge an air/surface interface, but if the building is as rigid as you say, lower frequencies are going to transmit the best throughout anyway. Floor joists are far easier to work with (from below), but if that is truly a concrete slab, it will want to resonate (if properly driven from below).
 

I don't think this will be an option. The floor probably isnt a concrete slab, like newer buildings. There's probably a support beam or some kind. The good thing is that the solid walls do not carry the sound. They are full heavy walls with no cavity space (bad for heat, great for sound blocking).
I currently live in a 70's apartment where all the footfalls from the flat below carry up the structure. The base sounds carry through the structure, but above all, the sound of dragging furniture carries like nothing else. In this other building, I'm hoping that the walls won't do that.

wst3
I was able to soundproof my second floor studio years ago with a layer of homosote covered with a layer of thick drywall and a layer of 3/4" plywood.

Just a quick question. Did you use the drywall on the floor? 
I've been thinking of making a floating floor system with drywall (due to its mass) instead of MDF or chipboard.
Has anyone done this? Is it do-able?

Thanks to Bill, I learned something new from this thread: Homosote. I had not been aware of this product. It seems to be some wonderful stuff! And I've got a building supply store right up the street that carries it.
 
Unfortunately, I've not been able to find any charts showing absorption characteristics across the spectrum, just STC and R-values. I'm concerned that it's just too light-weight to do much for low frequencies. Bill, did you find this material through your own research, or did you consult a builder/acoustician?

I've been researching soundproofing products for the past few years....it's a complicated business
I've used one product with good results Fonostop Duo is a product sold here in Italy, it's used for sound insulation, but mainly against footfalls coming from your own house. It's thin, relatively effective at blocking noise and easy to install.