my kitchen floor has been down about 5 years. in the past month it developed a slight "lump" and a squeak ,felt like a loose board. then it rapidly went from bad to worse- 3ft by 2ft bubble. when you walk on it it gives. It was installed over luan. Is it possible that the luan has buckled?? There is also a smaller bubble on the other side of the kitchen. This is on the second floor over the laundry room. Please help!