Introduction

Components of stairs

Types of stairs

Material

Points of consideration

Stairs consists of steps arranged in a series for purpose of giving access to different floors of building . Since stair is often the only means of communication between various floors of building, location requires good and careful consideration.

A stair is set of steps leading from one floor to other . It is provided to afford the means of ascent and descent between various floors of building. The room or enclosure of building in which the stair is located , is known as staircase.

The opening or space or occupied by stairs is known as a stairways.

In public buildings, stairs should be located near the entrance . In a domestic building, stairs should be centrally located to provide easy access to all rooms.

Stairs may be constructed by timber, bricks , stone, steel, or reinforced cement concrete.

Stair provide access and communication between floors in multi storey buildings , and are a path by which fire can spread from one floor to another , therefore, staircase must be enclosed by fire resisting walls , floors, ceilings and doors. It is desirable that lining to walls and ceilings are non combustible of low frame spread.

Stairs must be designed to carry certain loads , which are similar to those used for design of floors

TREAD- The upper horizontal portion of step over which foot is placed during ascending and descending a stairway.

RISER- The vertical of step . It is used to support and connect successive treads.

HEADROOM- The vertical height between tread of one flight and ceiling of overhead construction . It should be sufficient so as not to cause any difficulty to person using stairs.

NOSING- It is the projecting part of tread beyond the face of riser. It is usually rounded to give pleasing effect to tread and make staircase convenient and easy to use

LINE OR NOSING- This is the straight line touching the nosing or various steps and parallel to slope of line.

PITCH OR SLOP- Vertical angle made by line of nosing with horizontal .

LANDING- This is the horizontal platform provided at the head of series or steps. It is used as a resting place during use of stairs .It facilitates change of direction of flight .

HAND RAIL- It is an inclined at convenient height over steps .It serves as guard rail and provide assistance to user of stairs.

BLUSTERS- It is individual vertical member made of timber , metal or masonry fixed between string and hand rail to give support to hand rail.

STRINGERS- These are the sloping members of stair , used to support the end of steps.

WINDERS- These are the steps used for changing the direction of stairs . These are usually triangular in plan.

FLIGHT- This consist of series of steps provided between landing.

RUN OR GOING- Total length of stairs in horizontal plan including length of landings.

Single flight straight stairs Double flight straight stairs Qurter turn newel Half turn newel Open wall stairs Dog legged stairs Bifurcated stairs Circular stairs Spiral stairs

All steps lead in one direction

This way be continuous with two flights with an intermediate landing

Adopted when staircase is narrow and long

Provided mostly in porch , entrance etc.

Consist of two straight height flights running in opposite directions

There is no space between the flights in plan

Landing is provided at level which direction of flight changes

A stair turning through 90 degree with the help of level landing

Used in shops and public buildings

Popularly known as open well stairs

A well or opening is left between forward and backward flight

The opening is generally used for installation of lift

A short flight may or may not provided in these stairs

These stairs may have any geometrical shape and they require no newel post

This type of stairs is similar to open newel stair except the well formed between forward and backward flight is curved

Change of direction in such stairs is achieved by winders and not by landings.

All the steps are radiate from a newel post or well hole

All the steps are winders

This is provided where space is limited and traffic is casual

Mostly located at rear of building

These are light in weight and easy to construct but they have very poor fire resistance , They are used only for small rise residential buildings. Sometimes, fire resisting hard wood of proper thickness may be used.

These stairs are widely used at places where ashlars stone is readily available . Stone stairs are quite strong and rigid , through they are very heavy. Stone used for construction of stairs should be hard , strong and resistant to wear. The simplest form of stone stairs is those supported on both the ends , through an open well staircase can also be built.

These are not very common , except the entrance . However , brick stairs of single straight flight are often made in village houses. The stairs consist of either solid wall ,or also, arched openings may be left for obtaining storage space.

Stairs of mild steel or cast iron are used only as emergency stairs. They are not common in residential and public buildings, though these are strong and fire resistance. These are commonly used in factories, godowns, workshops, etc.

These are widely used for residential , public and industrial buildings. They are strong, hard wearing and fire resisting. These are usually cast –in- situ and a wide variety of finishes can be used on these.

LANDING – The width of landing should not be less than the width of stairs

WIDTH OF STAIRS - Residential – 0.8 to 1mPublic- 1.8 to 2m

TREAD- Residential- 220- 250mmPublic – 250-300mmnot less than 200mm in any case

RISER - Residential – 150- 180mmPublic – 120-150mmnot more than 200mm in any case

PITCH – Should not be more than 38 degree

-- MANISHA AGARWAL