I Can't Sleep These Days Because of the Footsteps Upstairs

Every night at 11 p.m., it sounds exactly like someone is banging on the floor with a wooden hammer. I've complained to the building management office twice, but it only stays quiet for that moment and then starts right back up.

I keep thinking moving out might be the answer, but I still have 8 months left on my lease... I'm just writing because I have nowhere else to vent.