STAIRS AND STAIR FRAMING` Prepared by

Ricardo Brown

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.

Lesson Objectives

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

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.

STAIRS

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

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

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

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

Stair Terminology

Rough Opening

The rough opening for the stairwell must be carefully laid out and constructed

Trimmers and headers should be doubled for support

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.

Designing Stairs

Questions