I wanted to run by some experts what I have been told is the best method for my application.

I want to install hardwood floors over a concrete slab. The structure is a multi level apartment building, so this is not in a basement, and as such, moisture is less of a concern I believe. I was told that the best method is to towel down a mastic, than lay 3/4" t and g ply and ramset the edges. then rosin paper and hardwood over that.

Sound right? Any other suggestions?

Thanks,
Andrew

Go to www.NOFMA.org Download or printout the information your looking for. It is all there. That way you get it straight from the guys that make the rules, without leaving anything out.

Just reread my post. I meant trowel down mastic with a notched trowel. Not towel. Sorry for the confusion. Thanks

You need to verify that it is in fact, concrete. Many multi-storied buildings use light weight cementious mixtures. One such type is Gyp-Crete:
http://www.maxxon.com/product_detail.asp?ID=1
One cannot glue or nail to it adequately. You best bet is to "float" your plywood subfloor. There has been much discusion on how to do this properly here. But basically, it entails two layers of 1/2 CDX plywood screwed together but running in opposing directions and overlapping the joints. Lots of work but not much more than gluing and nailing down 3/4" CDX. Another option is to choose a factory finished floor that can be floated in. Many options out there and they don't all look like plastic laminates.