Is spray-in foam useless for sound reduction?

[Rickster71]

-- looks like I'll have to start looking for another place. Damn.

If it's any consolation, it is a renter's market. Maybe you can look for a place that better suits your needs.
Possibly even a free standing house, instead of the apartment / condo multiple dwelling like you have now.
Good Luck

[highfigh]

Here's the thing about it -- she is not loud. It's just that the floors are so thin that any and all sound just passes right through. She doesn't mind it, but I do. She simply does not want to be imposed on at all with this construction (which would be two days max -- I even offered that she can use my apartment with me at a friend's place while it's being done, to no avail.) So it's not that she's overly loud, it's that this is an older building and she just doesn't want to help me out here, and is not being reasonable.

Hopefully the landlord will be a little more forceful with her when I tell him I'm going to leave.

As I said, she really has no say in the matter because it's the landlord who stands to lose if one of you decides to leave. It's an inconvenience for you but he will lose income and to him, that's not an acceptable option.

While you say the hardwood floors are beautiful, that's about the worst for sound isolation. A nice rug, large enough to cover most of the floor but leave a border, would not only make it more quiet, it will also improve your acoustics. If you put a non-slip mat underneath, it's even better.

[gmichael]

I might just have to do that. I've already been playing music at a louder level than I usually do, but again, it just doesn't bother her. I might have to go louder, but then that would make me look bad to the landlord.

Often, older people (I'm getting there myself) do not hear most frequencies as well as others. But most people can hear & feel bass well into their golden years. Maybe a couple of bass heavy movies are in order.