<p>This Architectural Drawing is AutoCAD 2d drawing of Stair foundation section in AutoCAD, dwg files. If cut stringers are used in the stair construction, then <strong>at least three stringers are required</strong>. Cut stringers should be spaced no more than 18 inches on center. For example, a 36-inch-wide stairway should have three stringers. If the stairway is wider than 36 inches, four stringers should be installed. For more detyails and information downmload the drawing file.</p>