Every stair refinishing job is hand work
A floor sander covers a room quickly. A staircase cannot take one at all. Every tread, riser, nosing, return and the awkward triangle where the stringer meets the wall is sanded by hand or with a small detail sander, and each of those surfaces then has to be coated separately with the same number of coats as the floor. That is why the honest unit is per step rather than per square foot, and why $80 to $200 a step covers such a wide band – a straight flight of open treads in good condition sits near the bottom, while a winder with returns, a worn nosing and forty years of carpet staples sits near the top.

