Stairways must be at least 36 inches wide and have a clear height of at least 80 inches along the stairway path and a profile length beyond the bottom step. Standing height is a vertical measurement from the leading edge of the tread to the upper ceiling. Each staircase must have a landing equal to the width of the staircase, but landing lengths greater than 48 inches are not required. Stairs with a total vertical elevation of more than 12 feet must have a landing between the upper and lower landings. A step is the flat, horizontal surface on which you walk. Tread depth is the distance between the leading edge or nose (a profile projection that protrudes from the underlying riser) from a step to the leading edge or nose of the next step, measured horizontally. This distance must be at least 10 inches. However, CCI notes that if the steps have no slopes and the steps have fixed risers and no open riser straps, the minimum tread depth is 11 inches. Helena, The item above You will see these standard step riser specifications raise the height (<=7.75" or in some codes <=7.0" or in Canada <=8.25") maximum and 4 inches (102 mm) minimum. The concern is that if you let the step go up less than 4 inches, you`re more likely to cause a drag trap.
For the elderly or anyone who has difficulty climbing stairs, it is very important to pay attention to all safety features such as lighting, handrails and, if necessary, colored buttons that show the edges of the steps. The maximum height of a riser is 7-3/4 inches according to the International Residential Code (IRC 318.104.22.168), measured between the leading edges of adjacent treads. In addition, the maximum permissible difference between climb heights is 3/8 of an inch. See also our blog post What is the steepest staircase allowed? Spiral and circular steps and stairs have special codes that apply only to them, as specified in sections 1009.7, 1009.8 and 1009.9 of the IBC. There are also alternating tread devices that are also permitted in special circumstances, as provided for in section 1009.10. How many steps would you need to have for a 29-inch high porch You can see from the chart that the minimum tread depth and maximum climbing heights vary greatly between different types of stairs. The profile and dimensions of the climb height depend on the standard stair angle. In general, steeper inclined stairs, such as ship stairs or ship ladders, have a smaller profile depth because as the stairs increase, the stairs at the top become an obstacle to the lower step. These are closed stairs (except for the missing broken riser on the first step), as the cast iron mesh defines the placement limits of the toe of a foot of someone climbing these steps. A stair lift (marked in yellow in our photo) is the vertical distance between the running surface of two steps (stair steps are what you walk on) – also known as stair climbing or climbing height.
[Click here to enlarge any image] I`ve been documenting steps and stairs and their handrails and railings in Mexico since 1960, so I know you`re absolutely right that there are a lot of high discounts and other step details across the country that can pose a tripping hazard. « 93% of Mexican municipalities do not have a building code. It`s not much more than paperwork anyway, says civil protection officer » – Mexico City Daily News, 19. September 2018, available online at mexiconewsdaily.com/news/93-of-mexicos-municipalities-have-no-construction-regulations/ The history of tolerance of high levels goes back more than a thousand years. This is a purely subjective opinion, but it has always seemed to me that if I were directing the construction of a pyramid – the highest stairs in Mexico – and given the time and effort required to get the materials to each of these upper stairs, I would have walked as high as possible. The example I illustrate below is from Palenque, Chiapas, in 2019. For other readers, Palenque was an important Mayan city that flourished between about 600 and 750 AD. The name Palenque comes from Spanish and means « fortified place », but the original Mayan name was Lakamha. In some cities, particularly Mexico City, where officials are aware of the dangers of earthquake damage, building regulations initially focused on earthquake-resistant construction. I recently ran into a problem where a concrete sidewalk was poured leading to an outside staircase from the porch, and the height of the slab made the first step much lower than the rest (similar to your photo of Quinn above).
As I understand the building code, this is a tripping hazard because it creates a very uneven climb and is therefore not compliant. Stair height measurement – The height of the stair step should be measured vertically between the leading edges of adjacent steps. In the United States, the step height standard should be between 7 or 7 3/4 inches and no less than 4 inches. You should take other steps if local building codes require it. In Canada, the maximum step height is 8 1/4 inches. As a general rule, the standard of variation between risers on a staircase is 3/8 of an inch. The nose of each tread shall not protrude more than 1 1/2 inches beyond the riser. Critical measurements such as standard stair width, climb height, and tread depth are not a matter of guesswork when renovating or building a home. Stairway measurements are determined by current practice and building codes, which in turn are often influenced by generally accepted practices. These rules aim to make stairs as safe as possible, so they should never be ignored or bypassed. OSHA and IBC determine minimum tread depths and maximum climb heights based on studies of stairs of different profile and climb dimensions.
A major 1976 study by John Templer showed that reducing tread depth to less than about 11 inches resulted in more missteps. Other studies have shown that missteps increase as tread depth increases. Based on these and other results, major building codes have adopted standards for minimum tread depth and climb heights. Therefore, the rules of design and projection of the nose of the staircase apply to these stages. In the photo, our yellow arrow points to the step and the white arrow to the stairs. • After how many steps/risers do you need a light above a staircase? Be careful not to confuse climbing heights with headroom heights or the total height of the stairs themselves. Headroom is the distance between a step and the ceiling (or appliances). There are also rules for the height of the standing height. If there are several centimeters of free space on the inside edge of a staircase, someone, especially a child with small feet, could easily enter that room and risk serious injury. The step depth of the staircase, also known as « running » step or horizontal distance in the direction of travel, is measured from the front edge of the nose of the step or from the edge of the step above to the leading edge of the step to be measured – the space under my foot in the photo above. In Guanajuato, my experience is that a major concern for building officials is to ensure that homeowners do not build above an authorized height or violate other more general guidelines, such as invading neighbors` privacy.
You will see that « stairs » or « stair codes » do not appear in this analysis.