HLF
Guide

Parts of a staircase

What the parts of a staircase and a railing are called, which measurements we need for the handrail, and how to take them – with drawings from our catalogue.

The stair and its parts

A staircase is made up of a few parts, and each of them has its own name. The drawing shows them on a straight stair.

Stringer
The side member of the stair, which the treads are fixed into.
Tread
The horizontal part of the step, where you put your foot.
Riser
The vertical piece between two treads.
Nosing
The front edge of the tread. The height of the handrail is measured from here.
Going
How deep the tread is, measured from front to back.
Rise
The height from one tread to the next.
Stair width
The overall width of the stair.
Total rise
The height of the stair, measured from finished floor to finished floor.
Landing
A level area between two flights.
Stairwell opening
The opening in the floor that the stair rises through.
Walking line
The line you walk along on the stair.
Straight stair: the measurements and the partsSection through a straight stair with a handrail. The handrail has an easing at the bottom and a knee bend at the top, and sits 900 mm above the nosing.Knee bendHandrailBracket spacing900 mmGoingRiseNosingTreadRiserStringerEasingTotal risePitchStair length – plan length
Straight stair: the measurements and the parts

The railing and the handrail

Handrail
What you hold on to, either on the wall or as the top of a railing.
Cap rail
The profile that sits on top of a railing or a wall.
Base rail
The lower rail of the railing, which the balusters stand in. It is matched to the cap rail.
Baluster
The vertical bars between the base rail and the cap rail, often turned.
Newel post
The sturdy post the railing is fixed to.
Newel top
The finish at the top of the newel post.
Flat bar
Flat steel that a timber cap rail is fixed to. It sits in a groove milled into the underside, running the full length or only where the cap rail is fixed.

Straight and winding stairs – what we need

All measurements in millimetres.

  • Plan length
  • Stringer length
  • Direction: whether the stair turns right, with the handrail in your left hand, or left, with the handrail in your right hand
  • Floor to floor, measured from finished floor (or the rise and the number of steps)
  • Rise (riser height)
  • Tread width
  • Going (tread depth)
  • Number of steps

Handrail on the inside of a turn

For the handrail on the inside of the turn to be made, the going has to be measured on every step in the turn.

Stair with a landing

The plan length is the length of the stair measured horizontally. The stringer length is taken along the stringer, at the pitch of the stair, and also gives the length of the handrail.

If the stair has a landing, the height from finished floor is measured for each flight as well as for the full storey height. Where the flight meets the landing, the handrail often has a knee bend and an easing.

Stair with a landing: the measurementsSection through a stair with a landing. Plan length and stringer length are taken for the flight, and the height is measured from finished floor for each flight and for the whole storey.Handrail withknee bend and easingPlan lengthFinished floorStringer length – handrail lengthGoingRiseFinished floorLandingStorey height, floor to floorTotal riseTotal riseStair length – plan length
Stair with a landing: the measurements

Spiral stair – what we need

All measurements in millimetres. For the plan radius, it is enough to give one of the four measurements R1–R4. From the measurements for the outer handrail we work out the production measurements for the inner handrail on the centre column.

  • Plan radius – one of the measurements R1–R4
  • Rise (riser height)
  • Number of steps
  • Number of steps per full turn
  • Direction: whether the stair turns right, with the handrail in your left hand, or left, with the handrail in your right hand
  • Floor to floor, measured from finished floor
R1
Centre of the column to the outer edge of the stringer
R2
Centre of the column to the inner edge of the stringer
R3
Centre of the column to the centre of the handrail
R4
Centre of the column to the centre of the stringer or cap rail
Spiral stair: plan radius R1–R4Plan and section of a spiral stair, showing where the plan radii R1–R4 are measured from the centre of the column.R4 (handrail/cap rail)R4 (cap rail)R3 (handrail)900 mmTreadTread width, outerGoing on the walking lineStringer – handrail/cap railOuter handrailTread width, innerInner handrailRadius of the columnWalking line
Spiral stair: plan radius R1–R4

Also tell us

This applies to straight, winding and spiral stairs alike.

  • Profile and dimension
  • Timber species
  • Finish
  • End detail
  • Bracket type
  • Size of the flat bar, where relevant
  • Indoors or outdoors

Bends

Corner bend, knee bend, easing, wreath 90°, wreath 180°, newel cap, barrier bend and end bend. What each one does, and where on the stair it sits, is explained on the bends page.

End details

Rounded end, chamfered end, stepped end, fully rounded end, vertical return, newel cap, volute, turned knob, end curve and end sleeve. Each of them is explained on the end details page.

Related pages

Any questions?

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