Can this floor be installed directly over an existing vinyl floor? The floor is going to be used for a pediatric physical therapy clinic.

You can install our 8mm Strong Rubber Rolls over an existing vinyl floor if you don't care about using the vinyl flooring as the main flooring surface going forward. Vinyl and rubber typically don't mix. Vinyl won't cause any issues to the rubber flooring, but the rubber flooring can potentially stain the vinyl. This process happens over a period of time and would make the vinyl unusable.