Underlayment for flooring is something that most people don't think about on a daily basis unless you are in an occupation which deals with flooring. Since the majority of people are unaware of the benefits of using underlay, it seems like a pretty obvious question to ask "well why would I need that?" Think of underlayment as the sidekick to your superhero flooring. Underlay helps the main hero 'flooring' to add additional warmth for your cold feet in winter, as well as adding sound reduction properties. Yes, you can have flooring without having the underlay, but the two really do work best together as a team.