Our home is 25 years old on a crawlspace. Im going to make my first attempt at installing laminate flooring in a bedroom approximately 13'X12'. When we built the house the builder used OSB. During construction the floor got wet and being young and dumb I didn't realize there was warping on the edges all over the place. The past is past.

Now after all these years my floors squeak in spots. I even screwed down the OSB in the great room a few years back when we had the carpet replaced. Within a few months the squeaks came back. And I know from seeing the OSB when the carpet was replaced that the builder used some kind of grinder to flatten high spots on the corners of the OSB wood when the house was built.

The bedroom in question does not have squeaks at this time but Im concerned when I rip out the carpet that OSB in that room also has some warping/cupping in spots like the corners of the OSB and may present a problem for the level of the laminate.

Im wondering if I need to put down some kind of other underlayment or a 1/4" layer of plywood ?