Builder doesn't want to solve the problem

[idcs01]

What is the name of your state? NY
We bought a new condo half a year ago. Couple of times we had problems with the hardwood floor. It was swolen in all rooms. Builder fixed it. But now the floor is "moving". There are a lot of chinks, cracks everywhere. We invited builder to see it. First his impression was, "we defenetely change it in all rooms", but later he said that he wants to fix it by using a "liquid wood". An independent contractor saw our floor and recomend us to put a new one because that "liquid wood" will come out in a week. Also, the floor will not look like a 6-months old, new floor, which it supposed to be. Three more appartments (there are only 10 units in a building) have the same problem. Builder was gonna give $2,000 to each apartment instead of changing the floor. We didn't take it because it's more than three times less than actual cost.
Can we (all 4 apartments) sue him? We really need your advise.
Thank you!

[djohnson]

What kind of warranty do you have when you purchased? When did the problems first start arrising? How can you prove it was the builders problem and not something you have done?