How much space is needed for a comfortable staircase: formulas for calculating the optimal dimensions of the span and steps, advice from the pros

Convenient staircase parameters, formulas and tables for calculation, personal experience

When starting to build a house, many imagine their future staircase, like a shot from the movie "Gone with the Wind": wide, sloping, opposite the main entrance, with wide railings. In reality, it may turn out that it is very difficult to fit even an uncomfortable staircase into a built house. In this article we will tell you how the FORUMHOUSE members calculate and build comfortable stairs.

 Content:

• Comfortable ladder parameters
• How to calculate span length and number of steps
• How much space to leave in the house under the stairs
• How to calculate winders

The main parameters of the stairs

The main criteria for a staircase in a private house are convenience and safety. The wider and flatter the staircase, the more convenient and safer it is, but it has to be designed based on the existing conditions, from how much space is left for it in the house.

To build a staircase in a private house, you need to know its basic parameters:

• lifting height;
• type of stairs;
• area in plan;
• steepness;
• number of steps.

You can't just take and assign these parameters, they depend on each other.

NickVas

FORUMHOUSE Consultant Moderator

For a straight staircase, the climb height and slope determine the plan area and conversely, the plan area and climb height determine the slope.

When designing stairs, online calculators set the values ​​of the defining parameters and calculate the steepness that determines the number of steps.

It has long been calculated and proven empirically that a ladder with the parameters that we have collected for you in a table will be comfortable and safe.

Comfortable and safe staircase parameters

If you do not follow the recommended parameters, the ladder will greatly lose not only safety, but also convenience. So, if you reduce the width of the tread below the limit indicated in the table, it will be difficult to go down it, and if you make it more than 300 mm, people will go astray.

The same is with the ascent angle: the steeper the ladder, the less space it takes up, and the more difficult it is to go down it.

Kate

FORUMHOUSE member

The steepness of a comfortable staircase should not exceed 45 degrees, otherwise you will have to go down it with your back forward.

And a "clearance" less than 1.9 m will cause any person of average height to reflexively tilt their head every time they step on the stairs.

Member of our portal with a nickname handur I assembled a "demonstration stand" of two steps from pieces of plywood, and checked on it how convenient the selected parameters were.

handur

I started with a tread width of 35 cm and a step height of 20 cm. I went up and down. Then I cut one centimeter from the height, assembled the stand and tried again.

It turned out that the height of the steps of 15 mm is just fine, 16 is very good, 17 is quite normal. The tread width - 35 cm is too spacious, 30 is quite normal. Then he made a tread width of 25 cm and made 5 cm by extension - the same width of 30 cm began to feel less comfortable: “if the space allows, then it is better to make a clean 30 cm, without outreach”.

How much space should be taken under the stairs

It will be correct to plan a place under the stairs at the design stage of the house. And, even if the house will be built according to a finished project, the parameters of the stairs must be rechecked. Especially if the space for the stairs is provided in a separate room - when the walls are set and nothing is allowed change, it may turn out that some 15-20 are missing to build a really comfortable staircase centimeters!

The placement of the staircase in the lobby leaves more room for maneuver, but this may be limited by the size of the opening in the floor and the location of the beams.

Ideally, you should leave a hole in the ceiling equal to the projection of the staircase, or leave it at least a meter wide, and in length - a value equal to the distance from the floor of the first floor to the floor of the second.

Floor beams should go along the future opening.

How to calculate the parameters of a comfortable staircase

The optimal parameters of a comfortable staircase can be calculated using several formulas. The FORUMHOUSE moderator will introduce us to them with the nickname Vit1959

Blondel formula (middle pitch formula):

S = a + h * 2
600 ≤ a + h * 2 ≤ 640

Safety formula:
a + h = 460 mm 

Convenience formula:
 a - h = 120 mm

• S in these formulas - the value of the average step

• a - tread width 
• h - step rise height.

In this case, the width of the tread should remain within the limits recommended by our table of 250-300 mm, the height of the steps - 150-200 mm.

Now, knowing the height from the finished floor of the first floor to the finished floor of the second, you can calculate the number of steps.

Vit1959

Let's say the height between floors is 3000 mm. And the range of convenient step heights is from 150 mm to 200 mm, on average – 175 mm. We divide 3000 by 175, we get 17.14 steps.

Now, taking into account the minimum tread width (250 mm), we determine the minimum comfortable length of the middle line of the march: 250 mm * 17.4 steps = 4285 mm (length of the middle line of the march).

Vit1959

Checking with our average step formula

600≤250+175*2≥640

The same dimension can be used when determining the length of the staircase.

Vit1959

I would not recommend doing less than it turned out in the calculations.

If the walls are already standing and the opening is made, the plan is checked for compliance with the "boundaries of convenience".

Vit1959

We put a possible place under the stairs on the plan, the stairs draw the middle line along the march and divide it by the estimated number of steps.

Now you should see if the parameters of the steps fit into the "boundaries of convenience" If not, you will have to look for other options.

How to calculate winders

If the parameters of the steps do not fit into the generally accepted, and the site will reduce the width of the tread to less than 250 mm, and the height of the step, on the contrary, will rise above the permissible 200 mm, they refuse the site and make cross-country steps.

Vit1959

Calculator programs use a reversal with three winders. In the vast majority of cases, this is not true.

The shape of the running lane (along which a person moves along the stairs) directly depends on the number of winder steps

With an increase in the number of winders, the running lane becomes smoother, it will become more convenient to go up and down such a ladder; but it will be more difficult to make such a ladder.

Regardless of where - at the beginning, in the middle or at the end of the march, the runways are located, they must comply with the principles of building stairs:

• the stroke line should not be winding (therefore, in the middle line of the march, the tread width should be more than 250 mm and the same throughout the turning part;
• in its narrowest part, the winder steps should be wider than 10 cm, and in the widest part - no wider than 50 cm.
• the minimum radius of curvature of the stairs in the turning part should not exceed 30 cm.

In conclusion - a universal recommendation for the most common situation.

gelar

FORUMHOUSE member

Those who deal with stairs know very well - as a rule, little space was left for it. And we need to look for a compromise, all we have at our disposal is a pair of "tread / lifting height". In apartment buildings and public buildings, under Soviet rule, the size of 300 mm and 150 mm was adopted - as the most suitable for all walkers - and grandmothers and children. Staircases were cast in housing construction with such dimensions. Everything else is from the evil one. In individual houses, deviations in the lifting height are possible, I usually take a tread of 275 mm (step width 300 mm) and h = 170-180 mm, Why 275 mm - lamellas of steps are mainly 40x40 mm and it is not very good for the glue seam to work on break. And with a width of 900 mm, I never do more than four steps in a race - it all passes on a piece of paper, but in fact it looks a little different.

And yet - I categorically discourage making risers in winding stairs - they sharply reduce the support area in a turn (in stairs up to 1000 mm wide). Formulas? Yes. If there is enough space. And so continuous compromises - the most important thing is to make the step and tread as close as possible to the starting size. And the lumen and so on need to be expanded and lengthened. And do not fool your head. And if we want everything to be a tube in a tube, then you need to think about the stairs at the design stage. Then everything will be according to the norms and formulas.

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More about how it should be arranged staircase in a private house, our article will tell. Find out more about how to check the planned stairs for compliance with safety and comfort criteria. A ladder can be not only comfortable, but also original if it is a double frame. A material for construction can be not only wood, iron or reinforced concrete monolith, but also aerated concrete. In the video - about a wooden staircase with winding steps.

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