1. STAIRS AND STAIR FRAMING

3. STAIRS
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

4. STAIRS
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.

5. Stair Terminology
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

6. Stair Terminology
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

7. Stair Terminology
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

8. Stair Terminology
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. Rough Opening
The rough opening for the stairwell must be carefully laid out and constructed
Trimmers and headers should be doubled for support

11. Stair Code

12. Stair Layout Measure total rise (from landing point)
Decide on number of risers based on 7” to 7 ½” risers (unless special circumstances prevent this)
Divide total rise by # of risers for riser height
Subtract # of risers by 1 for # of treads
Set stair jacks on framing square and trace onto stringer
Add and subtract as needed for top and bottom to adjust for actual floor heights

13. 9’ 2” 9’ 2” = How many inches total rise? 110”
What is the standard height of a step?
7” to 7 ½”
Divide total rise by standard riser height
110” / 7” = 15.71
110” / 7 ½” = 14.6
So… 15 risers and 14 steps
110” / 15 = 7.3” = single riser height
And standard 11” tread w/ nosing
9’ 2”

14. 15 Risers
14 steps
7.3” riser
11” step