The Stairway Level +4 4964 Sign will inform people that they are on this floor of a building. If using this sign, you should ensure that you also mark out the other floors of your building. You may wish to use the Floor 4953 sign with this.
Use one of these signs for both the lift area and the stairwell. The sign is a good way of preventing people from getting lost. People will have been used to seeing this sign in other buildings.
Fixing requires anything as simple as sticky pads, 'No-nails' type adhesive or double-sided tape.