You can lay our 1/2" Premium Mega Mats over low pile, commercial carpet with ease. Over high pile, thick padded residential carpet, there is potential for the mats to separate a bit when the pad underneath is depressed. This, in turn, can create a tripping hazard. To prevent this, we recommend placing a 1/4" plywood board under the mats. If you have light-colored carpet, we recommend placing a plastic sheet between the mat and the carpet to protect it from any staining.