I've purchased an engineered wood floor (plywood with wood veneer) for my living room . . . due to the fact that I needed a thin wood vs. thicker wood floor and I got a good deal at "Mah-dens."

My question for anyone in the know . . . the manufacturer doesn't recommend installing this on particle board . . . well nailing it or stapling it . . . which of course is what my 1970s vintage house has for a subfloor. I would rather not rip up the particle board and replace it . . . and simply throwing a layer of plywood on top of this floor will not work due to short ceiling heights and a tall grandfather clock.

So here's the gist of my question . . . or maybe it's questions . . . so far all I can tell is that particle board is not recommended subfloor material due to possible concerns with its holding power for nails and the possibility of swelling due to moisture. To my knowledge this floor has been down since the house was built in the mid-1970s and it shows no sign of swelling and ripping out the carpet tacks and staples was a bugger . . . which makes me wonder if the particle board might be OK to staple the engineered floor . . . or would I be better off gluing it down (I could go the floating floor route, but most floating floors I have seen have a cheap feel to them as they don't feel very "solid".)

Any suggestions? Staple 'er down and don't worry about it? Glue down? Float 'er and be safe?