Guidance for Designing

Spiral staircase

Our design office is at your service with dimensioning, drawing and designing of your spiral staircase.

Every spiral staircase is individually drawn, the drawing is sent to the customer for approval before manufacture commences.

When designing a spiral staircase consideration has to be taken to staircase radius, rise and number of steps per revolution.



Staircase Radius

The staircase radius is the measurement from the centre of the staircase to the outer edge of the handrail. Weland manufactures spiral staircases with a radius of 1´11 5/8” to 4´11 1/16”.



Rise

The rise should be chosen based on the given height between the landings. A suitable radius and the number of steps per revolution then determine the step rise.

The rise should be sized between 6 5/16" and 8 5/8". The lower the rise you choose, the deeper the step needs to be. The normal rise is about 6 11/16” to 7 1/16” mm.

The formula for the rise is 2 x h + W = 22 3/4" - 25 1/4".



Right or left turning staircase

Weland spiral staircases are manufactured with right or left turning. Right turning means turning to the right from the entrance point. (the centre tube to the right of upward travel).

Right turning

Right turning staircase

Left turning

Left turning staircase



Headroom

The headroom on the stairs must not be less than 78". The height is measured between two points located directly below each other.

Measure from the top edge of the lower step’s nose to the lower edge of the level’s (step) rear edge.



Number of steps per revolution

The figures to the right are a guide when determining the number of steps per revolution and the number rises. Count the number of rises between the landings and compare the values for the obtained rise.

Fields marked (green) in the table are the staircase dimensions that should be aimed for during the planning stage.

Radius steps / rev. Going on walking line* Suitable rise

1´11 5/8” / 14

1´11 5/8” / 15
1´11 5/8” / 16

6.18”

5.79”
5.39”

7 7/8” - 8 5/8”

7 7/8” - 8 5/8”
7 7/8” - 8 5/8”

2´3 9/16” / 15

2´3 9/16” / 16
2´3 9/16” / 17
2´3 9/16” / 18

7.40”

6.97”
6.54”
6.18”

7 7/8” - 8 5/8”

7 7/8” - 8 5/8”
7 7/8” - 8 5/8”
7 7/8” - 8 5/8”

2´7 1/2” / 16

2´7 1/2” / 17
2´7 1/2” / 18
2´7 1/2” / 19
2´7 1/2” / 20

8.50”

7.99”
7.56”
7.17”
6.81”

7 1/16” - 8 1/4”

7 1/16” - 8 1/4”
7 1/2” - 8 5/8”
7 1/2” - 8 5/8”
7 1/2” - 8 5/8”

2´11 7/16” / 16

2´11 7/16” / 17
2´11 7/16” / 18
2´11 7/16” / 19
2´11 7/16” / 20
2´11 7/16” / 21

10.04”

9.45”
8.94”
8.46”
8.03”
7.64”

6 7/8” - 7 7/8”

6 7/8” - 7 7/8”
6 7/8” - 7 7/8”
7 1/16” - 8 1/4”
7 1/16” - 8 1/4”
7 1/16” - 8 1/4”

3´3 3/8” / 16

3´3 3/8” / 17

3´3 3/8” / 18

3´3 3/8” / 19
3´3 3/8” / 20
3´3 3/8” / 21
3´3 3/8” / 22
3´3 3/8” / 23

11.57”
10.91”

10.31”

9.76”
9.29”
8.82”
8.43”
8.07”

6 1/2” - 7 1/4”

6 1/2” - 7 1/4”

6 1/2” - 7 1/4”

6 7/8” - 7 7/8”
6 7/8” - 7 7/8”
7 1/16” - 8 1/4”
7 1/16” - 8 1/4”
7 1/16” - 8 1/4”

3´7 5/16” / 18

3´7 5/16” / 19
3´7 5/16” / 20
3´7 5/16” / 21
3´7 5/16” / 22
3´7 5/16” / 23
3´7 5/16” / 24

11.69”

11.06”
10.51”
10.00”
9.57”
9.13”
8.74”

6 1/2” - 7 1/16”

6 1/2” - 7 1/16”
6 1/2” - 7 1/2”
6 11/16” - 7 7/8”
6 11/16” - 7 7/8”
6 11/16” - 7 7/8”
6 11/16” - 7 7/8”

3´11 1/4” / 17
3´11 1/4” / 18
3´11 1/4” / 19

3´11 1/4” / 20

3´11 1/4” / 21
3´11 1/4” / 22
3´11 1/4” / 23
3´11 1/4” / 24

13.82”
13.03”
12.36”

11.73”

11.18”
10.67”
10.20”
9.80”

6 1/8” - 7 1/2”
6 1/8” - 7 1/2”
6 1/8” - 7 1/2”

6 1/8” - 7 1/2”

6 1/8” - 7 1/2”
6 5/16” - 7 7/8”
6 11/16” - 7 7/8”
6 11/16” - 7 7/8”

4´3 3/16” / 18
4´3 3/16” / 19
4´3 3/16” / 20
4´3 3/16” / 21

4´3 3/16” / 22

4´3 3/16” / 23
4´3 3/16” / 24

14.41”
13.66”
12.99”
12.36”

11.81”

11.30”
10.83”

6 1/8” - 7 1/16”
6 1/8” - 7 1/16”
6 1/8” - 7 1/16”
6 1/8” - 7 1/16”

6 1/8” - 7 1/2”

6 1/8” - 7 1/2”
6 1/8” - 7 1/2”

4´7 1/8” / 20
4´7 1/8” / 21
4´7 1/8” / 22
4´7 1/8” / 23

4´7 1/8” / 24

4´7 1/8” / 25
4´7 1/8” / 26

14.21”
13.54”
12.91”
12.36”

11.85”

11.38”
10.94”

5 7/8” - 7 1/16”
5 7/8” - 7 1/16”
6 1/8” - 7 1/2”
6 1/8” - 7 1/2”

6 1/8” - 7 1/2”

6 1/8” - 7 1/2”
6 1/8” - 7 1/2”

4´11 1/16” / 22
4´11 1/16” / 23

4´11 1/16” / 24

4´11 1/16” / 25
4´11 1/16” / 26
4´11 1/16” / 27
4´11 1/16” / 28

14.06”
13.43”

12.87”

12.36”
11.89”
11.46”
11.02”

5 7/8” - 7 1/16”
5 7/8” - 7 1/16”

5 7/8” - 7 1/16”

6 1/8” - 7 1/16”
6 1/8” - 7 1/16”
6 1/8” - 7 1/16”
6 1/8” - 7 1/16”

 

= Staircase dimensions that should be aimed for.

The going* The going is calculated to be on an imaginary walking line 10" from the circumference.



Child Safety

By child safety we mean that up to 2´7 1/2” railing height no opening within the staircase is allowed to be larger than 4".



Handrail

As standard handrails are made of stainless steel tube, Ø 1.66"



Railing Height

The railing height is 3´7 5/16” from the front edge of the tread. Extra handrails are placed at an option height inside the balusters, for example, 2´11 7/16” . The railing height of the landing is 3´7 5/16” as standard.



Railing Loading

The railing is designed to withstand a load of 200# of handrail.



Stairtread Loading

The treads are designed for a spot load (4" x 4") of 674#



Clearance to Wall

The spiral staircase circumference must be at least 2" from the wall. The going is calculated to be on an imaginary walking line 10" from the circumference.



Stays

The spiral staircase must be fitted with stays every revolution (98.43" to 118.11" in height). This can be done using the square landing fixing. If the stairs have no square landing on each revolution, bracing must be fitted between the step and wall using custom stays.

Stays, vertical

When the spiral staircase cannot be braced to an adjacent wall, it needs to be stabilised using a vertical stay. These are attached at the bottom against the completed floor or foundation.



Landing Fixings

Use suitable type of bolt considering the material at the fixing points.



Baseplate Fixing

Use suitable type of anchor considering the material at the fixing point.

A base must be cast to fasten spiral staircases when there is no existing platform. Wind strengths, etc. must be taken into consideration when designing this.

Generally, the distance to the base plate from the wall must be at least the stair’s radius plus 2" mm.


There are no reference images for now.