Painting the interior of your home isn’t particularly difficult unless you have to paint a stairwell, which typically has 12 to 16 ft. tall walls and ceiling. The trick is to use two ladders: At the base of the staircase, lean an extension ladder against the wall. And stand a stepladder on the upper landing. Then lay a scaffold plank across the two ladders, making sure it’s level. Clamp the plank to prevent it from sliding or shifting.