Thus, we calculate: Every staircase should have a landing at the top and bottom. 5/16 in. If the stairs have open risers, the open space between the steps cannot be large enough to allow a 4-inch sphere to pass through. ANSI A117.4 Accessible and Usable buildings and Facilities (earlier version was incorporated into the ADA), ASTM F 1637, Standard Practice for Safe Walking Surfaces, (Similar to the above standard, [7] The Circular Staircase, Mary Roberts Rinehart, [8] Construction Drawings and Details, Rosemary Kilmer, [9] Falls and Related Injuries: Slips, Trips, Missteps, and Their Consequences, Lawyers & Judges Publishing, (June 2002), ISBN-10: 0913875430 ISBN-13: 978-0913875438, [11] The National Institute of Standards and Technology, NIST (nee National Bureau of Standards NBS) is a US government agency - see, "A Parametric Study of Wall Moisture Contents Using a Revised Variable Indoor Relative Humidity Version of the "Moist" Transient Heat and Moisture Transfer Model [copy on file as/interiors/MOIST_Model_NIST_b95074.pdf ] - ", George Tsongas, Doug Burch, Carolyn Roos, Malcom Cunningham; this paper describes software and the prediction of wall moisture contents. Staircase measurements are determined by common practice and by building code, which itself is often informed by generally approved practices. Most importantly, stairs that are not wide enough can be dangerous during a fire, as they might impede escape. The greatest riser height within any flight of stairs must not exceed the smallest by more than three-eighths inch. As we explained above, the most common stair riser defects likely to lead to a fall include: Nothing is right about the exterior stairs shown in our photo (at left ) from a 1991 home inspection: See DECK STAIR BUILDING START for more details. A prime example is the standard stair width. Not all staircase measurements are universally the same in all parts of the country, though. x 48 in. Rise/Riser: The rise, or height of a step is measured from the top of one tread to the top of the next … The standard height of stair risers is around 7.5 inches. The difference between the largest and smallest tread depth or riser height cannot be more than 3/8 inch. These stair treads are also too short in depth, less than 10" and so are under-sized. In my understanding of the building code this is a trip hazard as it creates a very unequal riser and thus is not compliant. Riser and tread dimensions should be continuously uniform for safety; building codes limit variation to 3/8" | 10 mm The underside of risers should be sloped or have a 60° angle minimum between nosings and the horizontal surface Open risers are not allowed under ADA guidelines These data demonstrate that work on and around ladders and stairways is hazardous. Open riser stair treads should be to 9 1/4" in depth and will typically be greater at shorter stair riser heights. Introducing "One Thing": A New Video Series, The Spruce Gardening & Plant Care Review Board, The Spruce Renovations and Repair Review Board. Exception: Private stairways serving an occupant load of less than 10 and stairways to unoccupied roofs may be constructed with an 8 inch maximum rise and a 9 … Berendt, John, Midnight in the Garden of Good and Evil, A Savannah Story, Random House 1994, ISBN 0-679-42922-0 pp. These rules are aimed at making staircases as safe as possible, so they should never be ignored or bypassed. Staircase width refers to the side-to-side distance if you were walking up or down the stairs. This stair stringer is too-deeply notched and could split; The stair risers are too high, as our client is showing with our tape. [27] "The Dimensions of Stairs", J. M. Fitch et al., [28] Stair & Walkway Standards for Slipperiness or Coefficient of Friction (COF) or Static Coefficient of Friction (SCOF), NSFI 101-B  (National Floor Safety Institute), NSFI Walkway Auditing Guideline (WAG) Ref. at STAIR RISER SPECIFICATIONS. A staircase that goes up 12 feet and has steps that are 7.5 inches tall will take up around 13 feet and 6 inches if it has 9-inch long steps, but making it with 11-inch steps will take up around 16 feet and 6 inches. Stairs that are too narrow are a hazard in many ways. Item #1336217. Four risers or steps, Randy, and as we calculate the riser height as 29 / 4 we get each step rise height as 7 1/4" tall. This distance must be at least 36 inches and does not include handrails. Smith Stair Systems 7.5-in x 48-in Dark Walnut Prefinished Red Oak Stair Riser. Question I have an enclosed staircase with a knee wall and banister on the right side. Subtract 6–7 feet (1.8–2.1 m) from the total rise to account for headroom. Grossman, Samantha, "WATCH: Everybody Trips on This One Subway Stair", [Video], Time Magazine, (29 June 2012), [After this video of a problematic Brooklyn subway staircase went viral, the MTA stepped in to fix the problem. All risers and all goings in the same flight of stairs shall be of uniform dimensions within a tolerance of ±5 mm. Therefore the rules for stair nose design and projection apply to these steps. Headroom is defined further Reader comments are invited. Building stairs for your deck is often considered “the most difficult part of” the construction project. Cali Bamboo 7.5-in x 48.0-in Bourbon Barrel Prefinished Bamboo Wood Stair Riser. - PDF Document from NIS, [12] Slips, Trips, Missteps and Their Consequences, Second Edition, Gary M. Bakken, H. Harvey Cohen,A. Stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. 7" Riser Height / Tread-Depth-Y = 0.7535 = 37° slope Basic stair riser height dimensions required for safe stairs. More importantly, they show that compliance with OSHA's requirements for the safe use of ladders and stairways could have prevented many of these injuries. Im not a lawyer, but in my experience the building owner has responsibility for hazards at their own property. Or see STAIR RISER HEIGHT FAQs questions & answers posted originally on this page. For any staircase that has six or more risers, there must be a wall switch at each floor level to control the light source. The riser height shall be measured vertically between the leading edges of adjacent treads. July 30, 2009. Item … even where disabled individuals are not the design target. Riser thickness of 1 inch; And a stringer width of 12 inches; ... Now, using a standard mount staircase, the vertical height rise of the steps will be one step less than with a flush mount because the final step is taken up by the decking. ), [39] "How Slippery Is It", retrieved 8/29/12, original source, [41] Frictional Coefficients of some Common Materials and Materials Combinations, The Engineering Toolbox, retrieved 8/29/2012, original source: [copy on file as Friction and Coefficients of Friction.pdf ], [43] International Building Code, Stairway Provisions, Section 1009: Stairways and Handrails, retrieved 8/29/12, original source: [copy on file as IBC Stairs Code.pdf], [44] Model Building Code, Chapter 10, Means of Egress, retrieved 8/29/12, original source:, [copy on file as NJ_Bldg_Chapter10.pdf] adopted, for example by New Jersey. Note: appearance of your Comment below may be delayed: if your comment contains an image, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. At a riser height of 5 1/2" the stair will be at a "critical angle" where a ramp would be more appropriate. It pushes the whole stairway out by the depth of the stair tread in move that would be unnecessary - but then I can't see your situation, perhaps I'm missing something. STAIRS, RAILINGS, LANDINGS, RAMPS - INSPECTIONS, CODES. Someone may have fallen into these stairs because several years after I took the photo above I found that the property owners had added a filler across the open space at the inside edge of the stair treads. 101-A& 101-B (may appear as ANSI B101.0) sets rules for measuring walkway slip resist, OSHA - (Dept of Labor CFR 1910.22 does not specify COF and pertains to workplaces) but recognizes the need for a "qualified person" to evaluate walkway slipperiness, ADA (relies on the ANSI and ASTM standards)Â, [29] A. Sacher, International Symposium on Slip Resistance: The Interface of Man, Footwear, and Walking Surfaces, Journal of Testing and Evaluation (JTE), ISSN: 1945-7553, January 1997  [more focused on slipperiness of polished surfaces, [30] Algae is widely recognized as a slippery surface - a Google web search for "how slippery is algae on steps" produced more than 15,000 results on 8/29/12), [31] Slipperiness of algae on walking surfaces, warning, Royal Horticultural Society, retrieved 8/29/2012, original source:, [32] Slipperiness of algae: "Watch your step, wet rocks and algae are slippery" Oregon State University warning  1977  retrieved 8/29/2012, original source:Â. As long as the 3-foot width standard is met, you can expand the stairs' width as far as you wish. Different dimensions for open versus closed riser stairways. The riser height is to be measured vertically between leading edges of the adjacent treads. Stair risers are detailed Best Practices Guide to Residential Construction, by Steven Bliss. The minimum width for stairways shall not be less than 36 inches clear. To meet building codes requirements. Add a headroom measurement of at least 6–7 feet (1.8–2.1 m) to prevent injuries. Stairs within dwelling units may have a maximum rise of 7 ¾ inches and a minimum run of 10 inches. Open riser stair treads must be at least 1 1/2" thick because the tread, not supported by a riser, may otherwise split. Please see complete details Risers (the vertical element connecting treads) that are no less than 6 inches in height and no more than 7.5 inches. Watch out: at STAIR RISER SPECIFICATIONS and at STAIR DIMENSIONS, WIDTH, HEIGHT you'll read that stair risers should be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. Compare; Find My Store. A stairway in which there is a noticeable variation between the risers is a safety hazard. The tread depth is measured from the forward edge of the step nose or edge of the step above out to the leading edge of the step being measured - the space beneath my foot in the photo at left. What is the building code for building stairs from first floor to second floor in Maryland.. Open riser stairs are allowed a"back slope of at most 1 1/2". Be sure to check with your permitting agency about building codes that apply to your locality. Continue reading at STAIR TREAD DIMENSIONS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX. Take a look at the sketch of stair specifications at the top of this page. [3] "The Elimination of Unsafe Guardrails, a Progress Report," Elliott O. Stephenson. The following staircase code requirements pertain to straight-run stairs. ADA (Americans with Disabilities Act), Public Law 101-336. Suggestions for adapting pre-fabricated stairways to the to the actual overall stairway height without violating building stair codes & standards. ISBN 10: 1-933264-01-2, available from the publisher, Lawyers ^ Judges Publishing Company,Inc.,, [13] Slips, Trips, Missteps and Their Consequences, Gary M. Bakken, H. Harvey Cohen, Jon R. Abele, Alvin S. Hyde, Cindy A. LaRue, Lawyers and Judges Publishing; ISBN-10: 1933264012 ISBN-13: 978-1933264011, [14] The Stairway Manufacturers' Association, (877) 500-5759, provides a pictorial guide to the stair and railing portion of the International Residential Code. The treads and landings of all straight-run staircases should have an artificial light source capable of lighting the treads and landings to no less than 11 lux (approximately 1-foot candle). Divide the height of the stairs by the desired rise. For a 6" riser a comfortable tread would be 13 1/2". Because more people are injured by trips and falls than other hazards, experts have looked closely at the specifications for stairs, steps, and rails to reduce the falling hazards. ISBN-10: 0471648361, ISBN-13: 978-0471648369, Hardcover: 320 pages, available from and also. Red Oak and Primed Reversible Riser The Reversa-Riser from Surewood-LNL is the The Reversa-Riser from Surewood-LNL is the perfect riser to use for stair remodels. retrieved 8/29/2012, [34] Jinjin Li, Yuhong Liu, Jianbin Luo, Pengxiao Liu, and Chenhui Zhang, "Excellent Lubricating Behavior of Brasenia schreberi Mucilage" Langmuir 2012 28 (20), 7797-7802, [35] Jason R. Stokes, Lubica Macakova, Agnieszka Chojnicka-Paszun, Cornelis G. de Kruif, and Harmen H. J. de Jongh, "Lubrication, Adsorption, and Rheology of Aqueous Polysaccharide Solutions, Langmuir 2011 27 (7), 3474-3484, [36] "Coefficients of Friction for Ice", The Physics Factbook™, Glenn Elert, Ed., retrieved 8/29/12, original source:, [38] Serway Physics for Scientists and Engineers 4th edition (p. steps may be under 7 " high. Model #LJ80757X48-O DW. Templer, John. for pricing and availability. Nearly half of these injuries are serious enough to require time off the job--11,570 lost workday injuries and 13,312 non-lost workday injuries occur annually due to falls from stairways and ladders used in construction. My question is, who is responsible in terms of an accident or lawsuit. We have no relationship with advertisers, products, or services discussed at this website. at STAIR DESIGN for SENIORS. They are closed riser stairs (except for that broken missing riser at the first step) because the cast iron gridwork defines the limits of placement of the leading toe of a foot of someone ascending these steps. However, if the steps do not have nosings, and the steps have solid risers, not open risers, the minimum tread depth is 11 inches. Definition of & specifications for open riser & closed riser stairs. It has a primed side that can be painted any color you wish or flip it around to reveal an unfinished, red oak side that can be stained to match your other red oak decor. Stair tread depth is more of an issue for descending, rather than ascending, stairs. We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need. When designing a staircase for use in a home, designers need to keep in mind not just the comfort of those traversing the stairwell, but also how much space the stairs will take up. Stair tread depths shall be 11 inches (279 mm) minimum. This beautiful stairway is in the old central Post Office building in Mexico City. Nosings must project at least 3/4 inch and no more than 1 1/4 inches beyond the riser below. S. Hyde, Jon R. Abele, ISBN-13: 978-1-933264-01-1 or This may also lead to a user looking away from their path for their head to clear the obstruction. Step riser specifications riser height (<= 7.75" or in some codes <= 7.0" or in Canada <=8.25") maximum and 4 inches (102 mm) minimum. -- IBC, IRC, BOCA, Kingston NY Stair Code, & other sources. Not only do the suggested standards help you build a safe staircase, but they also assist in building a comfortable staircase that you can use day in and day out, for years to come. For more information, see Section 1011 of the 2015 International Building Code for a more in-depth look at commercial stair requirements. International Code Council, 500 New Jersey Avenue, NW, 6th Floor, Washington, DC 20001, Tel: 800-786-4452, Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the, Decks and Porches, the JLC Guide to, Best Practices for Outdoor Spaces, Steve Bliss (Editor), The Journal of Light Construction, Williston VT, 2010 ISBN 10: 1-928580-42-4, ISBN 13: 978-1-928580-42-3, available from Open riser stairs (shown at right in the sketch above) do not include a solid board or other material that fully encloses the open space between stair treads. Apologies for the delay. [4] "Are Functional Handrails Within Our Grasp" Jake Pauls. A step tread is the flat, horizontal surface … The minimum depth, measured in the direction of travel, is 36 inches. Most straight stairs have a typical riser height between 7” – 7.5” whereas spiral stair riser height has a maximum riser height of 9.5”. Click to Show or Hide Citations & References, OSHA estimates that there are 24,882 injuries and as many as 36 fatalities per year due to falls from stairways and ladders used in construction. Reader Question: 28 April 2015 Cynthia Johnson said: What are the best dimensions for seniors with physical limitations i.e. 126. Detail stair treads and risers complying with the following: Minimum 11-inch tread width Exception: Minimum 10-inch width within dwelling units Minimum 4-inch and maximum 7-inch riser height Exception: Maximum 7-3/4-inch height within dwelling units Uniform tread width and riser height on each stairway flight 64-65. A stair riser (green arrow in our photo at above left) is the vertical distance (green arrow) between the walking surface of two stair treads (treads are what you step on) is the stair riser or riser height. code requires a maximum RISE of 7" and minimum RUN of 11". Awkward positioning of these items may lead to falls. Vol. Topics here include Allowable variation in stair step riser height by code & to avoid tripping. There is no railing at all along these stairs (and the height above ground is more than 36" which means that in just about every jurisdiction stair railings would be required by the building code). Yes, Stair widths with a minimum of 22 inches If there are more than four stairs in a stairway, they must have fixed railings with heights that vary depending upon use. That keeps us close to the ideal or desired step height. Have a maximum riser height of 9.5 inches (24 cm); 1910.25(d)(3) Have a minimum headroom above spiral stair treads of at least 6 feet, 6 inches (2 m), measured from the leading edge of the tread; Steps for built all risers and treads for the same height contractor came in and put blue stone in and now the bottom step is a lot smaller for the riser is that okay will it pass inspection? 6.75 or 7.2 are allowedRisers should, however, be uniform, Is there a step riser height less than 7 inches, Helena,The article above you will see this standardStep riser specifications riser 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 make the step rise less than 4 in you're more likely creating a tow catching trip hazard.for seniors or anyone who has difficulty climbing stairs it's very important to attend all of the safety features such as lighting, handrails, and where appropriate color keys showing the edges of steps>. 7/26/90 is very often cited by other sources for good design of stairs and ramps etc. This may alter B or C above. Stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3/8 inch. Staircase Calculation Formula is . Critical measurements such as standard stairway width, riser height, and tread depth are not a matter of guesswork when you are remodeling or building a home. Stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. Further, the tread measurement of every tread in a stairway should be as close as possible to identical. Additionally, the riser measurement of all of the treads should be as close as possible to identical. InspectAPedia tolerates no conflicts of interest. Handrail Spindle Spacing for Stairs and Landings Item #17656. Perhaps at night or in dim light, someone walking near the center of these steps is going to go sailing. x 7.5 in. The reason for this is that as all the treads are set to a near 30 degree angle. Staircase riser height translates to the distance you move your foot either up or down from one step to an adjacent step. To simplify the process, we’ve created this deck stair calculator to help you determine the … This article provides building code specifications, sketches, photographs, and examples of the proper stair step height or stair riser dimensions and other stair riser requirements for indoor or outdoor stairways. 1011.5.2/R311.7.5.1 Riser Height and tread Depth Stairs shall have a maximum rise of 7 inches and a minimum run of 11 inches. Many communities adopt the International Building Code wholesale, while others make modifications. Where there are several inches of open space at the inside edge of a stair tread someone, particuarly a child with small feet, could easily step into this space, risking serious injury. The tread depth (TD) is to be ≥ 185mm and it should not be more than 30mm shorter than the going (G). Stair riser heights The riser height shall be measured vertically between the leading edges of adjacent treads. Winding stairs and spiral stairs have several different code requirements. Except as permitted for dwelling units and by Sentence, STAIRS, RAILINGS, LANDINGS, RAMPS - INSPECTIONS, CODES, ARTICLE INDEX to STAIRS RAILINGS LANDINGS RAMPS, Stairways and Ladders, A Guide to OSHA Rules, HOME INSPECTION EDUCATION COURESES (Canada), HOME INSPECTION EDUCATION: HOME STUDY COURSES. Total Required Number of Risers = Total Stair Rise / Height of One Rise = 60” / 6” = 10 Riser. Staircase risers should be adequately deep to allow a majority of your foot to have enough room to rest on the stair. In all the buildings handrail height should be between 900mm and 1000mm measured from the top of the handrail to the pitch line. The riser height shall be measured vertically between the leading edges of adjacent treads. Closed riser stairs include a board or other solid material that encloses the vertical space between stair treads. John Wiley & Sons, 2006. That's an interesting question; you're basically extending the floor area by the width of a stair tread, right? inch variation in riser height within a flight of stairs. We compare the code requirements for closed riser and open riser stairs and we include other basic stair tread and riser dimensions. Or simply put, open riser stairs have no enclosure (my toe, shown above would be facing into open space). Stair treads must be of uniform size and shape except the largest tread run within any flight of stairs must not … But a local building code inspector MIGHT interpret that top tread as a stair top platform. We would need change the stair tread depth to make a 37° slope stair that has an acceptable 7-inch riser height. Maximum 7 inch stair riser height and minimum 4 inch stair riser height. This distance must be at least 10 inches. Short risers can also make the staircase longer, which could add to the cost of construction. TREADS AND RISERS 2. Staircase Calculator. Eg. At any point on the staircase, a user should have a full 6 feet, 8 inches minimum vertical distance between the top of the stair tread and the bottom of the ceiling. The greatest tread depth within a flight of stairs cannot be more than 3/8 inch larger than the smallest tread depth. The stair tread is the horizontal walking surface (red arrow) of an individual step. Watch out: As my foot illustrated in the photo below, we often find open riser stairs that are unsafe because the tread inner edge does not extend beneath the outer edge of the tread above. Mit Press, 1995. Having the right calculations before getting started can make the task a lot easier. I checked further into the above stair formula and found that it only applies at a riser height of 7" or greater. (C) The greatest tread depth within any flight of stairs may not exceed the smallest by more than 3/8 inch. This work has been translated into stair and railing specifications that are similar among codes and countries (but not identical). Closed riser stairs (demonstrated at left by the author's granddaughter Quinn Morgan Gilligan) include a vertical riser board (that my toe is kicking against). Affi et als (2014 and earlier) have weighted the contributions of various stair features to the risk of a stair fall, considering for example, straight versus turned stairways, with or without landings, number of steps, handraiil design, lighting specifications, and step design specifications (using a tread depth of 269mm and a riser height of 174mm with a 40 mm tread nosing in a case example to state various risk contributors. Don't confuse step riser height (defined above) with stairway headroom - the vertical space between the walking surface of a stair tread and the ceiling or other obstruction overhead. Minimum 11 inch stair tread depth. The lovely stairway shown at left rises to the main entry for the Maria Mitchell Observatory on the Vassar College Campus, Poughkeepsie, New York. Headroom refers to the height between the top of the stair to the ceiling. The deck and platform railing is open with no balusters. We also discuss the allowable variation in stair or step riser height between individual steps in a stairway. depth beyond the bottom riser. The stair riser height calculated from the stair's total rise and number of risers needed. 7.5-in x 48-in Unfinished Red Oak Wood Stair Riser. If the vertical space between stair treads is open (see our photo at left) the space is still a stair riser, but it's an "open riser". If the sidewalk builder has a license can they be held accountable for their mistake? The minimum stair riser is 5". The width of the landing, measured perpendicular to the direction of travel, must be no less than the width of the staircase. A stair riser is the back, vertical part of a step. Can the top tread of a stair stringer be the same elevation as the finish floor ? This should be no more than 7 3/4 inches. The largest nosing projection cannot be more than 3/8 inch greater than the smallest nosing projection. A platform needs to run no less than 3 ft. in the direction of travel up and down the stairs, and yours would run what, maybe 11" - or whatever is your tread depth. 7 is a recommended riser height, not the only one allowed. Risers, goings and treads dimensions. As a general rule, stair risers should not be less than 4 inches (10 cm) tall, but their height should not exceed 7.5 inches (19 cm). In any case, the local code is what you must follow to pass inspections. Keep in mind the straight stair riser height and spiral stair risers height is different. [26] >Steps and Stairways, Cleo Baldon & Ib Melchior, Rizzoli, 1989. ], retrieved 2016/06/27, original source: Here's a long discussion about how to do it. Rectangular tread depths shall be 11 inches (279 mm) minimum measured horizontally between the vertical planes of the foremost projection of adjacent treads and at a right angle to the tread's leading edge. If she does, then the stairs would be improper as the platform would be very much too short. Note: For commercial stairs, I.B.C. L.J. Minimum Head Height clearance is 78 inches. Staircase Riser Height: 7 3/4 Inches, Maximum, Staircase Tread (Run) Depth: 10 to 11 Inches, Minimum, Staircase Headroom: 6 Feet, 8 Inches, Minimum, Stair Design Ideas: Metal Balusters, Railings, and Posts, Stone Steps vs. This means your stair risers should be less than or equal to 7 3/4 inches. Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly. This code specification was developed to prevent stairs from being too high if walking upstairs or too low if descending. I’ve recently come across an issue where a concrete sidewalk was poured leading up to an exterior porch stair, and the height of the slab made the first step much lower than the rest (much like in your picture of Quinn above). The marble stair treads are a bit slippery and there is no handrailing along the lower rounded steps, but the tread dimensions are correct and comfortable. Lee has over two decades of hands-on experience remodeling, fixing, and improving homes, and has been providing home improvement advice for over 12 years. Solid Risers (IBC 1011.5.5.3) Solid risers are required for IBC stairs except for means of egress stairways as long as the opening between treads does not … STAIR WIDTH. Also, it’s important to note that risers built inside tend to be a few inches shorter than those built for the outdoors. Or does the homeowner become responsible for allowing it to happen and paying the sidewalk builder prior to realising it wasn’t to code? Get daily tips and tricks for making your best home. (1) for fire escapes, steps for stairs … I don't think we'll find an explicit prohibition in the stair codes, since the code writers can't and don't try to anticipate every possible variation on what people may invent. If the vertical space is enclosed (see our Carson Dunlop sketch at the top of this page), the enclosing board is called the stair riser. Experts suggest that for more physically limited people the best way avoid falls is to seek living accomodations on a single floor. Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia. The riser height shall be measured vertically between the nosings of adjacent treads. Anyone walking up or down the stairs should have plenty of clear headroom without having to duck down. Stair calculations: how to calculate custom stair tread & risers based on stair rise & run measurements. A step tread is the flat, horizontal surface that you walk on. Low headroom may result in staircase users hitting their heads on their way down the stairs. Staircase code states that stairs must be 3 feet wide or wider. The stringers, 5 treads, and 6 risers, installed in 1965, were not cut correctly. Concrete Steps in Gardens, Deck Code Guidelines for Guardrails and Stairway Railings. What is minimum stair riser height for outside stairs ( such as for making it easier for elderly people to climb)? Or see the ARTICLE INDEX below for detailed articles on specifications for proper dimensions for stairs, railings, platforms. Photo by permission. Please make use of the below calculator (Input the Values in Inches) Total Required Number of Tread = Total Stair Tread or Run/ width of one Tread = 90” / 10” = 9 Tread. But are these open risers or closed riser stairs? The greatest riser height within a flight of stairs cannot exceed the smallest by more than 3/8 inch. The run must not be less than nine inches. Obviously the original builder shouldn’t be, if they built a compliant stair, so I’m thinking the person who built the sidewalk should be responsible for fixing it (even if stairs are not their area of expertise) as they created the problem. At the same time, staircase code measurements do allow for some flexibility, since most measurements are accompanied by minimums or maximums. Correcting Stair Riser Height in Place An old stair stringer with incorrect riser dimensions needs fixing, on site. Rheumatoid Arthritis? (B) The minimum tread depth is 9 inches measured from tread nosing to tread nosing. Stair safety hazards, photos of defects & Sketches of stair design requirements. In other words, the space must be slightly less than 4 inches high. Open stair risers with a more than 4-inch opening are a child hazard, as we detail below. Now when … The size of stair risers can vary depending on the total amount of space available, design aesthetic, or personal preference. Sketch at page top courtesy Carson Dunlop Associates. at STAIR HEADROOM. The staircase: history and theories. Stairs do not need a handrail on the bottom two steps. [33] Coefficient of friction of algae on surfaces [like stair treads]: Delphine Gourdon, Qi Lin, Emin Oroudjev, Helen Hansma, Yuval Golan, Shoshana Arad, and Jacob Israelachvili, "Adhesion and Stable Low Friction Provided by a Subnanometer-Thick Monolayer of a Natural Polysaccharide", Langmuir, 2008 pp 1534-1540, American Chemical Society, STAIR RISER SPECIFICATIONS at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice. [copy on file as ] -, [19] Common Sense Stairbuilding and Handrailing, Fred T. Hodgson, [21] Building Stairs, by pros for pro, Andy Engel, [22] A Simplified Guide to Custom Stairbuilding, George R. Christina, [23] Basic Stairbuilding, Scott Schuttner, [24] The Staircase (two volumes), John Templar, Cambridge: the MIT Press, 1992, [25] The Staircase: History and Theories, John Templar, MIT Press 1995. The minimum clearance shall be maintained the full width of the stairway and landing. How many steps would you have to have for a 29 inch high porch, Sounds like a trip hazard, that's the first concern, and yes, quite possibly your local building code official will object. 1. Staircase Tread (Run) Depth: 10 to 11 Inches, Minimum. I'm not sure what to say about this remarkable stairway found in Oxaca. Narrow stairs make it more difficult to carry items up and down the stairs. If your deck is 56 inches (140 cm) off the ground, … Why would you do that? See your question you posted at The tread depth is the distance from the front edge, or nosing (a tread projection that overhangs the riser below), of one step to the front edge or nose of the next step, measured horizontally.