With the considerable help of Jeanine and Nicolai, we completed the installation of the stairs at the River House today. Once the top and bottom cleats (see photo below for an example of each) were secured to the landings, it took only a matter of minutes to set the stringers and attach the treads. The top cleats are secured with four 1/2″ x 5-/1/2″ lag screws and the bottom cleats with three. What I could not know when designing these stairs was how stiff they would feel once erected. Happily, I can report that they are extremely stable, stiffer than the stairs in any home we have ever lived in. Additionally, the design tolerates movement of the house framing with changes in humidity or aging. In total, I would estimate that it took 80 person-hours of labor and $7,500 in materials for this project. Not bad compared to the quote of roughly $40,000 we initially received (and that did not include installation labor or the 20% markup charged by our builder).