Does the Hendo board need a specific floor underneath it? https://www.kickstarter.com/projects/142464853/hendo-hoverboards-worlds-first-real-hoverboard
Quote from the page you linked to:
Currently, this surface substrate needs to be a non-ferromagnetic conductor. Right now we use commonly available metals in simple sheets, but we are working on new compounds and new configurations to maximize our technology and minimize costs.