The “nail down” method is the most common and preferred way to install hardwood floors. This method works for solid and engineered floors, but only with a wood subfloor. The nails are nearly invisible after installation.
The “glue down” method uses an adhesive to adhere hardwood flooring to the subfloor. This method works with a cement or wood subfloor, and reduces the likelihood of deflection between the flooring and subfloor – which means less chance of squeaking.
A floating floor is installed by attaching each board to the next, tongue-to-groove or glued, and at the end joints. The flooring is installed without any adherance to the subfloor. This method is ideal if the subfloor is tile or vinyl.