Solid Hardwood, Engineered and Laminate Flooring - subfloor for hardwood

plan on putting down hardwood floors in a 200sf workshop/studio. is the 3/4" plywood subfloor enough to nail the flooring to? will the nails/staples penetrate the subfloor?

Yes 3/4 plywood is fine as long it's not particle board. Yes the nails will stick about 1/2.

Use a product such as Advantech or Home Advantage which is tongue and groove, and wax impregnated to alleviate moisture problems. Lay down a moisture barrier such as rosin paper and lay the flooring. Don't worry about the nails sticking through. It would be worse if they didn't grab completely.

Rosin paper is not a vapor retarder or a vapor barrier. It has a permeance rating of about 50------ like your newspaper! Do not use rosin paper over concrete, crawlspace, laundry room, bathrooms, or other water source, it does nothing.

15# felt paper (5 perms), or H.D.'s ---product called Aquabar B, is another semi-permeable choice. Be safe, GBAR

If you use a felt product don't overlap it, as it will throw your flooring off by the thickness of the felt. You don't really need much of a "vapor" barrier anyway. Moisture from the top, such as in a laundry, bathroom, etc. won't be helped by any moisture barrier anyway.

I wanted to clarify what I was saying. farayray, you didn't say what you are going over, I was covering all the bases, so to speak, with the semi-permeable floor paper.

If it is over, say a wet basement, you would want more than rosin paper( it absorbs water). Otherwise, you would be relying on the sub-floor ply or wood, only, to stop moisture from getting to the new wood above.
Aquabar- B is thinner than 15# felt paper, so it sould be overlapped 4+". Here :

http://www.fortifiber.com/pdf/install_guides/IG_aquabar_b.pdf

The 1st page is wood floors, 2nd tile and stone.

I didn't mean the moisture is in the room with the new floor, that's what the finish is for. Sometimes my kids don't understand me either, imagine that. lol Be safe, GBR