Will this product stay put without slipping if it does not go edge to edge, all the way to the walls? I have a 13" x 10" room and want to cover a 9' x 9' area. If I add the edge pieces to 3 x 3, 3' tiles, are the finished dimensions 9' x 9', or do the edge pieces add to the measurements?

You can install our 3/8" Sport-Lock Rubber Tiles in the middle of a room without any glue. Many of our customers install our rubber tiles like this and have done it successfully since 2007! The weight of the tiles helps to keep the flooring in place. Also, rubber has a high coefficient of friction. These two features help to keep your interlocking rubber tiles in place. The finished dimensions of your floor will be very close to 9' x 9' when installed.