Stair Design and Construction

What we need to know about stairs

Interior designers can really make a statement with stairs. The design and finish of the stair (unlike a colour or wallpaper or even a lighting system) will usually be a permanent feature of a home or building. Although they are functional they have an aesthetic prominence as well and therefore it is important to understand how they are constructed, what the components are and the various systems or designs that can be used to establish the design parameters.

What are they?

They are a system of steps that allows the passage of people and objects from one level to another. They can be made from timber, concrete and sometimes steel or stone aluminium and with modern technology and materials even glass.

Definitions

Flight, The steps between levels including landings.

Landing, An area at the top or part way up the stair that either acts as a resting place, a change of direction or is the end of the stair.

Tread, The surface of a step, which you tread or step on.

Riser, The distance between each step. I.e. the vertical space between each step.

Nosing, The front edge of the step or tread that hangs over the riser.

Going, The measured horizontal distance between nosings.

Rise, The actual or measured distance between treads.

Total Rise, The total vertical distance from floor to floor.

Total Going, The total horizontal distance of the stair.

PitchLine, An imagined line that stretches from nosing to nosing for the length of the stair.

Pitch, The angle that the flight of stairs is built at.

Headroom, This is the distance from the pitch line to the next surface above it. E.g. the ceiling or soffit above. The normal minimum is two metres.

String, The angled beam or member at each side of the stair that supports the treads.

Wall String, As above but fixed to the wall.

Outer String, As above but independent of the wall.

Designer Note. Stairs tend to take up a great deal of room. They are functional as well as aesthetic. Consequently the type of stair employed will be determined by these three factors.

The Function, The Look, The Available Space

There are many forms of different stair layouts from a straight flight, to a series of intricate curves and landings, however the basic principle of stair design does not alter. Stairs should be comfortable to walk up not only for the young but also for the old.

The steeper the stair the more difficult it will be to climb. A steep stair can be compensated with additional landings. However it will be a balance between the amount of room you have for the stair and the distance between floors.

The going will always be shorter than the tread but the tread should be, if at all possible large enough to accommodate the whole of the human foot.

Think of access between levels as a generous stair or a mean stair.