Similarly with stair carpet, you need to clean off the old coverings before you put down the underlay. Prise out tacks and nails, repair loose treads (the bits you step on) and risers (the upright sections between each step). If the carpet is cut from a roll you might want to consider buying enough to continue it into the hall. Whether laying vinyl or carpeting it is important to get your floor preparation right to ensure the maximum life possible.