Our Eco-Flec Rolls do not have to be glued when installed. The sheer weight of the product, in most instances, is enough to keep the flooring in place. If there is movement due to certain exercises being performed, then we recommend using some double sided carpet tape under the rolls. When we talk about plush carpet, we are really talking about the pad that is under the carpet. Most homes have a plush carpet with a thick pad under it. These pads are typically about a 1/2" thick. Since the pad is very soft and is meant to depress when weight is applied to it, there can be instances where the rubber on top can be depressed as well creating a potential tripping hazard. If your carpet doesn't have a thick pad under it, then this is not an issue, but if it does, then there can be a potential issue.