Ted, I have to agree with Jim. I recently laid peel and stick tile. My mistake. I used 1/4 inch underlayment in a kitchen. Even though one side of the underlayment was smooth, there were places where the tile didn't want to stick. Guess I should have put the good side up. In the other room, I used Medium Density Particle board and it stuck well. OSB isn't nearly smooth enough to lay Peel and Stick. If you could get it to stick, it would show every imprefection in the floor. Sorry.