my question is it ok to install 3/4in nailed down hardwood floors over waferboard . or is this just another name for a particle board or oriented strand board

Best to consult manufacterer of subfloor. NWFA says OSB is an acceptable substrate for 3/4" nail down flooring. I prefer plywood but many builders like OSB because it's CHEAPER. OSB is not particle board. I think waferboard and OSB are the same thing.

Some of the OSB used around here is better then others. Some of it is pure junk and will not hold a fastener, tightly. Sqeak, squeak squeak!

I didn't like it when it first came out, and i still don't like it. I will use a bead of construction adhesive on each plank, where the fastener will penetrate the bottom.

Live and learn on that one, and I don't trust it, as it has caused problems in the past.

The term "OSB" has become a nebulous one. Regular OSB is rarely used as decking anymore. Advantek and similar products have supplanted the OSB market in my area. Advantek is great stuff. It pales in comparison to real plywood,but it is pretty good stuff,nonetheless.

Wafer board is OSB. You can nail to that stuff,but you had better make chalk lines on your felt that coincide with the joists and make sure you secure your floor at those joists. I double up on fasteners when I am nailing over that stuff.

Chuck, With all due respect, using 3/4" T&G flooring and 3/4" OSB, the 2" fastener that is nailed diagonally through the tongue will barely penetrate the bottom surface of that OSB panel. You may think you are getting more "bite" out of your fastener by trying to nail into the joists/trusses but in reality, very little of that fastener is hitting the joist. Face nailing is another story. I learned this from the advanced NWFA installation school. Regarding doubling up on fasteners, the nailing schedule for strip flooring is 10" to 12" apart; for plank it is 8" apart. If you double up, your'e nailing every 4" to 6" apart and risk splitting the tongue on solid wood; especially maple and braz. cherry. If the subfloor is suspect as to it's suitability, either overlay with 1/2" plywood or get a waiver.

I have never understood that either Chuck. I don't mind chaulking lines or taking more time but what would it really accomplish doing that.

I understand the need when I face nail, but field nailing?
I am ignorrant. What am I missing here.

I agree with the advantec, much better product.