Wood frame, residential construction: Workers push second floor preframed dimension wood exterior wall frame up into position. Wall was framed on horizontal, either on the second floor on which workers are standing or at some other place on the site and then brought into this position by the tower crane. After it has been pushed vertical, it will be supported in vertical position by diagonal braces as can be seen through the window of the wall panel to its left. Note the diagonal 2"x4" boards nailed on edge on both sides beside the windows, which give the framed wall sufficient strength to resist lateral loads during construction. Ann Arbor, Michigan 2004.