The Auxx-Lift could be mounted on any ceiling (rafters/joists/sloped ceiling) THIS KIT IS OPTIONAL: Typically the lift's motors operate parallel on the ceiling joists. In order for you the motors to operate perpendicular to the joists you will need this kit. This extra kit will switch the platform ninety Levels https://garrettcioua.scrappingwiki.com/1525040/5_essential_elements_for_auxx_lifts