I am putting a play structure in my backyard which is dirt at the moment, but I will be putting in grass. I would like to have a section for rubber tiles under and around the playset in the middle of the gras?s yard. However in the future, I may want to move the playset to a different spot. What tiles would be best over dirt and also be able to be pulled up and installed in a different area if I decide to move the playset in a couple of years? I don't want to use mulch because my dog will eat it. I live in southern California.