Abstract: A device for blocking stairs which is attached to the vertically-extending side panels of a stairway. A pair of expanding support elements is wedged between the side panels and separated from each other by a few steps. A material sheet is attached to, and extends between, the pair of expanding support elements. The material sheet covers the few steps so that access to the steps and the stairway is blocked. The support elements include outwardly-biased end plates equipped with rubber pads. One of the support rods has a rotationally-biased spool for retracting the material sheet during transport or storage.