Hi,
We are looking at installing 1/2" or 3/4" hardwood flooring. It's going in an 11'x18' room with a fireplace. The room currently has carpet. I looked under the carpet, it has 5/8" particle board with 1/2" OSB under that.

Can I use long enough staples or nails to go down into the OSB, or do I need to remove the particle board, and put down another layer of OSB or plywood?

Thanks, Jeff

I would rip up the PB and put down some good Plywood .

Unless you install a floating floor, or a glued down floor that accepts a particle board underlayment, you must remove the particle board. Both NOFMA and the NWFA say to never nail a floor down over particle board. Manufacturers agree. Even if you float or glue a floor down, particle board stands a greater chance of swelling and crumbling due to it's make up. It's used because it's cheap; not because it's good. Read this "sticky" listed at the top of this this forum index.

http://hardwoodflooringtalk.com/phpbb2/ ... .php?t=385

Yup. gotta rip that "stuff" out and install minimum 1/2 inch plywood. And for the price difference, unless it would interfere with stair rises, or doorway thresholds, would use 3/4 ply and be done with it.