We built an inlaw suite in our 2 bay garage last fall. Because it was at a lower level than the house, the subfloor was raised about a foot. This allowed easy plumbing and wiring. The joists were correctly laid and plywood was put on top.The Pergo had its own underlayment. It looks great (wide plank rustic chestnut). After a few months, it began to pop in certain areas when walked on. I mean a REALLY loud popping sound that wakes one up at night. It started in the den and has now spread to our bedroom. Someone told us the apply a board over the affected area and hammer it hard. That was no solution. Can anyone help with this maddening problem? Have others experienced this?