STAIR CASE ANATOMY
Here are some staircase terms and the recommended guidelines for a staircase design that is ergonomic and safe.
This is the total height of the stairs, determined by the sum of the risers’ height and number of steps.
The total dimension of the treads. The run and gradient of the stairs are related – for a gentler ascent (deeper treads and lower risers), you will need a longer run.
The stair treads are where you step on while climbing the stairs. The ideal depth of each tread should be at least 25cm.
All risers should be the same height. Varying heights break the rhythm as calculated by the brain, which can lead to tripping. The ideal height should be no more than 18cm.
The housing on the sides of a flight of stairs. A staircase can have two stringers (on either side), or just one (in the middle as a supporting beam, or on the outside).
This is a practical feature, necessary for heights from 1m, as it prevents falling off an open side. It can be designed in numerous ways. For example, it can be composed of balusters and a handrail made of wood, or glass panels. The ideal handrail height is between 75cm and 95cm. For comfortable gripping, the ideal width of a handrail is between 3cm and 6.5cm.
The nosing is the edge finishing of the treads that makes the stairs more comfortable to climb. However, it mustn’t overhang too much, lest it becomes a tripping hazard. The ideal range is 0.6cm to 2cm.
A flight of stairs should not have a rise with a height of over 3.6m between landings or floor levels. (That equates to around a maximum of 20 risers.) Landings provide a transition between flights of stairs, and should have a minimum depth of 90cm.