Abstract: A scaffold assembly including a ladder unit having an outside vertical member with a hollow top end and bottom end, an inside vertical member connected to the outside vertical member by horizontal steps, the top step and the bottom step having a hollow end adjacent to the point at which they are connected to the inside vertical member, the hollow top end and bottom end of the outside vertical member being adapted for connecting to another ladder unit by placing a pin in the hollow portions of the two vertical ladder units, the ladder unit being adapted for joining side by side to another ladder unit by placing a horizontal joining member in the open ends of the top and bottom steps to join the two ladder units horizontally side by side.