Calculation of straight stairs on broken strings – Online calculator with the drawings

Straight welded ladder calculator with zigzag bowstring

Stairs on a broken kosour are one of the most common and easy-to-manufacture structures on a metal frame, since they are a simple welded structure in the form of a zigzag made of profile pipes and do not require additional installation of supports (fillies) to fix the steps. Also, all other things being equal, they are the cheapest structures among traditional materials (wood, concrete...), have increased maintainability, are durable, strong and do not contribute to the occurrence of creaks.

The online calculator for calculating a straight metal staircase on polyline slits allows you to create a ready-made design project that contains a comprehensive estimate for manufacturing with optimal material consumption, a set of highly detailed drawings of the main elements, an interactive 3D model to assess the shortcomings of the proposed object and recommendations for assembling the most comfortable structure for operation. All calculations are saved in your personal account and are available for download.

Procedure of settlements

• Step 1. Choose the most acceptable units of measurement – mm, cm, m, inches, feet.
  
• Step 2. Select the drawing method: monochrome or color.
• Step 3. Determining the configuration of the stairs – right-hand (with a left turn), left-hand (with a right turn).
• Step 4. Sizing ladders – length, width, height of the opening ^{(if the top step at the level of the 2nd floor, the height of the opening = height of the stairs)}.
• Step 5. Selection of stages and related variables – number of steps, the thickness of the steps, the protruding edge of the steps, the upper level below level 2 on floor or level (optional).
• Step 6. Defining the parameters of a polyline skew – the height of the pipe section, the width of the pipe section.
  
• Step 7. Installation of additional jumpers between skewers (optional item) – the height of the pipe section, the width of the pipe section.
• Step 8. Risers (optional item) – the ability to account for the risers of the stairs based on the thickness of the Board.
  
• Step 8. Characteristics of the elements of fence – the height of the handrail, the baluster section, the thickness of handrail width of handrail.
• Step 9. Overlap and walls – must be filled in for correct visualization (does not affect the parameters of the stairs).
• Step 10. Confirm the entered parameters and start calculating the straight staircase on the polyline after clicking the button "Calculate".

Design features / designations in drawings

Recommendations

Creating an effective and reliable welded frame staircase is possible only if the calculations are performed correctly – the calculator fields must be filled in in accordance with the actual size of the opening, and the parameters of the main elements are made taking into account the basic rules of ergonomics of the design, which we suggest using. The image below shows the values that were obtained in a practical way based on the formula "convenient stairs" by the French architect Francois Blondel. Other characteristics can be found on the page "Calculation of stairs".

• h – the height of the steps;
• s – tread width;
• 60/65 cm – the average length of a person's step.

However, our calculator does not take into account compliance with construction regulations and state standards, but at the same time does not allow entering critically unacceptable values. Therefore, in order for the ladder on the zigzag string to turn out not only comfortable and practical, but also safe, you need to familiarize yourself with the provisions of the technical documentation. The most informative are:

GOST 23120-78 "marching stairs, platforms and steel fences", GOST 25772-83 steel fences for stairs, balconies and roofs, SNiP 21-01-97 (SP 112.13330.2011) "Fire safety of buildings and structures", SNiP 31-02-2001 (SP 55.13330.2010) "single-family residential houses", SNiP 2.08.01-89 "Residential buildings", SNiP 2.08.02-89 (SP 118.13330.2011) "Public buildings and structures", SNIP 2.01.07-85 (SP 20.13330.2010) "loads and impacts».