Floating, Nail or Glue…Which one should I do??
There are three ways to install a hardwood floor, float it, nail it, or glue it. Here are some guidelines to choose what is best for your situation. Do you have a raised foundation? If the answer is no- you cant nail. Floating is glueing (or some flooring are click lock and do not require glue) tongue and groove and free-floating over a pad, held down by gravity. This has expansion limitations because the floor expands exponentially across the room. Installer needs to pay special attention to leave expansion space around the entire floor and between rooms (tmolds in doorways). This includes end molds to exterior doors, undercutting fireplaces or leaving tmolds to tile. Because a glue down floor is stuck directly into the glue and has little wiggle room to effect the boards next to it, people are less particular about expansion with glue down floors (for example foregoing the tmold transition to tile). Just make sure to leave ample expansion at the walls under the baseboards because the floor is still going to grow in response to humidity!

What is the difference?
The floors are going to perform the same: they will dent/scratch/wear
the same on top. But they
1) Sound different
2) feel different
3) cost different.

A floating floor sounds more like a nail down installation over a crawlspace. Some people don’t care, some people HATE that sound. Pad adds acoustic absorbance (that is why it is required in condos for your neighbors) and is also easier on the knees and back. And, finally, the glue and moisture barrier are expensive! And a little added labor. You are looking at $1.50 more per square foot,
which ends up being a significant price jump in the project. So- if you don’t care- float. If you like it to sound “solid” or hate tmolds- glue. And if you have the option: nail.