Hi Steven, these are really light. There is a 1" space all around the back between backer and the wall. Usually we recommend just one drywall screw into the wall to hang these small pieces, two if you dont want it to tilt if someone touches it. If the wall is concrete, you probably only need to go in an inch to get the screw to bite into the wall, other than that there is no worry about being able to hold the weight, since the piece is only about 3-4 pounds...