2. `Prepared by Ricardo Brown

3.  Describe what stair construction is.  Define terms associated with stair construction.  Calculate the unit rise, unit run, angle of incline, and number of treads for a stairway given the total run and rise.

4.  STAIR – a series of steps, each elevated a measured distance, leading from one level of a structure to another.  “Flight of Stairs” – a continuous series of steps without breaks formed by landings or other constructions

5.  Types of Stairs ◦ Main Stairs  Straight Run, Platform, and Winding ◦ Service Stairs  Stairways are usually not built or installed until after interior wall surfaces are complete and finish flooring has been laid.

6.  Stairwell – the rough opening in the floor above to provide headroom for stairs  Stringer – one of the inclined sides of a stair that supports the risers and treads  Riser – the vertical surface between two treads  Tread – the horizontal face of one step

7.  Nosing – the part of the tread that extends over the riser beneath it  Newel – the post that supports the railing  Handrail – an angled piece supported by a wall or railing intended to be grasped by persons  Balusters – vertical members supporting the handrail on open stairs

8.  Platform – a horizontal area placed between to flights of stairs  Landing – the floor at the top or bottom of each story where a flight of stairs begins or ends  Winders – Wedge-shaped treads installed where stairs turn  Unit Run – the width of a tread minus the nosing

9.  Unit Rise – the height or a riser; vertical distance between two treads  Total Run – the sum of all unit runs  Total Rise – the sum of all unit rises  Headroom – the vertical distance from a step to a ceiling above

10.  The rough opening for the stairwell must be carefully laid out and constructed  Trimmers and headers should be doubled for support

11.  Stair Angle should fall between 30 and 35 degrees  The sum of two risers and one tread should be 24 to 25” G+2R =550 – 700mm  The sum of one riser and on tread should equal 17 to 18”  An 11” run and a 7” rise follows all three rules.