HOW TO DESIGN A SAFE AND COMFORTABLE LADDER

Stairs are access to a residential or multi-storey building that connects the lower floors to the upper floors. Everyone with different preferences usually chooses their favorite staircase, but mainly they can be grouped into three main types: wooden stairs, metal stairs and concrete stairs. So, how do you know which staircase is right for your house, how do you calculate and plan the material on the stairs?

**Regardless of the design of the stairs, you must follow general guidelines:**

- Size: 0.9 – 1.2 meters wide.
- The formula: 2h + b = 600 mm (where h is the step height, b is the step width). In architectural works, the height of the silver staircase in the house is usually 150 to 180 mm, the width of the stairs reaches 240 to 300 mm, respectively.
- Number of levels: Must be at birth is best: that is, the number of degrees of multiplication 4 + 1. For example: 4 * 5 + 1 = 21 degrees.
- Fence height: Usually 900mm.

* Note: The calculation of the steps is based on the number of steps you descend from the start to the end of your household (upper floor). If your staircase has a projection screen then the projection also counts as one ladder step.

Have we ever felt that a good staircase design will make going up the stairs feel comfortable, not tiring and there is a game between indoor and outdoor staircase designs? Here is a little discussion about the ladder design problem.

Let us look at the architectural design of the house, surely the problem of stairs has its own points.

As we know, a ladder consists of several steps, which means it also consists of a step (the horizontal side where the foot treads) and the height of the ladder (the vertical side which is the distance between the bottom step and the step above it).

Here is an effective formula created by the architect Francois Blondel, France – which can help us to accurately and efficiently calculate the size of a staircase according to its function.

Example of a scheme for the design of a steep staircase with low traffic:

- Height of stairs = 22 cm (there are 2)
- Width of steps = 22 cm (there are 1)

Then:

(2 × 22) + (1 × 22) = 66 cm

Example of an optimal stair calculation scheme:

- Height of stairs = 18 cm (there are 2)
- Width of steps = 28 cm (there are 1)

Then:

(2 × 18) + (1 × 28) = 68 cm

Example of a scheme for calculating loose steps, especially for the outdoors:

- Height of stairs = 14 cm (there are 2)
- Width of steps = 39 cm (there are 1)

Then:

(2 × 14) + (1 × 40) = 67 cm

Example of calculating the number and height of stairs at a floor to floor height of 2.6 meters (in cm to 260 cm):

**How to count the number of steps (Formula A)**

For example – the height of each rung is 18 cm, the formula for calculating the number of steps needed is;

260/18 = 14.44 => we round up to be 15 steps.

**How to calculate the height of each rung (Formula B)**

Then we divide the height from the floor to the floor by the number of steps we have obtained from formula A;

260/15 = 17.33 cm

**How to calculate the width of the step of the steps (Formula C)**

From the Brondel formula we want the result to be in the range 63 to 65;

(2 x 17.33 cm) + (1 x footing) = range 63 to 65

34.66 cm + (1 x footing) = range 63 to 65

(1 x footing) = range 63 to 65 – 34.66 cm

Now, from the range of numbers 63 to 65, what number do we want to choose? for example 64? Then;

(1 x footing) = 64 – 34.66 cm

(1 x footing) = 29.34 cm

So the end result is;

15 steps with a height of 17.33 cm, and a width of 29.34 cm steps.

Want to use the number 63? Yes, just replace 64 with 63, want 65, yes, just replace the number 64 with 65 – and so on.

**Frequently asked questions**

How high is the staircase that is considered ideal / comfortable? (Update 30 apr 19)

the ideal is 16-18 cm. Want it to be more comfortable, it can be 14-15 cm, only some say it’s too sloping like an incline (I really like it). Now, just enter the height of the footing in ‘Formula A’ and ‘Formula B’ above 🙂

Except when forced or for service areas and those that are rarely traveled, it can be 20 cm or more. In fact, some are up to 25, even 30 cm (the name is also ‘forced’).

If the height of the steps is more than 18 cm, what is the problem?

High steps will make climbing tired. Especially if the distance between the floor below and above is very high, it can cause shortness of breath, lots of stairs, high altitude….

How to calculate the width of the stairs?

Depending on its usage and local regulations, the minimum recommended width is 80 cm for stairs in the house, and more than 1 m for public buildings, depending on the number of people who will use the stairs.

As a reference, as taken from the architectural book by Ernst Neufret, “Art of Projecting in Architecture”, with a staircase width of 1.25 m, the ladder must be able to accommodate 2 people at once in ascending and descending conditions; and at 1.85m wide, it can fit 3 people at the same time with a reasonable distance of 55 cm between the person and the handrail.

Ideally, each ladder should have no more than 15 steps in a row.

How wide is the landing?

The recommendation is that the floor gap must be the same size as 3 steps wide, or there is also another standard that the landing width is equalized to the width of the stairs.

What is the ideal height between the stairs and the ceiling?

The minimum height between each rung and the ceiling is 2.15 m. According to Ernst Neufert, a minimum of 2 m is tolerable. Handrail height varies between 80 – 90 cm from each rung.

To what extent can we modify the calculation of the steps and height of the steps?

In terms of shape and configuration, stairs can be made in various ways. However, the calculation of the step and the height of the steps must be the same and appropriate in the process of calculating the design to avoid imbalances that can arise when using them, either when climbing stairs or in descending conditions.

This formula can help us make accurate calculations in designing stairs. Even so, each calculation must take into account the specific characteristics of each project, as well as the building rules that apply in the area.

Hopefully this is useful.