The riser shall be measured vertically between leading edges of the adjacent treads. The maximum width of a public staircase is 1800mm. The maximum riser height shall be 7 3⁄4 inches (196 mm). Staircase code states that stairs must be 3 feet wide or wider. Stair riser heights shall be 7 inches (1 78 mm) maximum and 4 inches (102 mm) minimum. Uniformity and Tolerances for Risers, Runs and Treads 1)Except as provided in Sentence (2), risers shall be of uniform height in any one flight, with a maximum tolerance of a) 5 mm between adjacent treads or landings, and b) 10 mm between the tallest and shortest risers in a flight. Length of Staircase. r+R = 17 1/4" (good) To be able to fit mine in there would need to be three stairs on the corner. Winding stairs and spiral stairs have several different code requirements. The riser height shall be measured vertically between … Looking for a little more info give this blog a read... run R = 11" You could change that to 17 risers at 6.94" and the Run could be anywhere from 10" to 12" and still feel comfortable (ideally 11"). Spiral Stair Riser Height Requirements. The riser height shall be measured vertically between the leading edges of adjacent treads. For more information, see Section 1011 of the 2015 International Building Code for a more in-depth look at commercial stair requirements. 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 … On my first stair, r+R was roughly 15 inches—way too far from 18” to be comfortable or safe. You could change that to 17 risers at 6.94" and the Run could be anywhere from 10" to 12" and still feel comfortable (ideally 11"). Stair " rise height" is the vertical height or distance between the surface of two stair treads (what you actually step on). A stair riser is the back, vertical part of a step. The minimum tread depth is 11 inches. 1. Maximum stair step riser height (<= 7.75") or in some codes <=8" Minimum stair step riser height: >= 4" Step riser height uniformity <= 3/8" variation between successive step surfaces, or … 9.8.4.4. STAIR WIDTH. Austinindian, the rise and run your architect designed is well within the comfort zone, though a run of 10 1/2" might be slightly more comfortable. Framing Project Guide. Run x rise = (70 to 75), Any idea how to add it to the graphic representation? Now when … 2r+R = 22" (too low) https://www.aricgitomerarchitect.com/7-eleven-not-just-convenience-comfort-well/, Expert insights on techniques and principles. Or if your design allows, you could have 18 risers at 6.56" with a Run of 12". Stair tread depths shall be 11 inches (279 mm) minimum. Although the rise itself wasn’t terrible, something about using it felt very cramped, and I set out to find what went into a safe, comfortable stair. This distance must be at least 36 inches and does not include handrails. run R = 4" The value for the Actual Riser Height property changes to accommodate the stair height change. Dimensions for Risers (1) The rise, which is measured as the vertical nosing-to-nosing distance, shall conform to Table 9.8.4.1. Trusted, in-depth guidance from the pros for framing a durable, code-compliant house. rise r = 7 3/4" If a stair meets both numbers, it will be comfortable. Additionally, the riser measurement of all of the treads should be as close as possible to identical. Outside of the yellow zone represents a stair that most people will find uncomfortable in some way. Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine. For example, your floor-to-floor height as designed might be 118" (16 risers at 7 3/8"). The rise plus the run (r+R) should be within an inch of 18”. Stair Riser Height Measurement. The maximum of 18 risers in a flight. If it meets only one of the numbers, it will be less comfortable. Can someone further explain? rise r = 7" Here’s a good example of a stair I don’t think anyone would mistake for being comfortable. I included icons for each of the stairs described in this article: Sign up for eletters today and get the latest how-to from Fine Homebuilding, plus special offers. The width of the landing, measured perpendicular to the direction of travel, must be no less than the width of the staircase. 2r+R = 25 1/2" (within range) The riser height shall be … 1.2. The greatest riser height within a flight of stairs cannot exceed the smallest by more than 3/8 inch. 27.2 TREADS AND RISERS On any given flight of stairs, all steps shall ha ve uniform riser heights and unif orm tread w idths. PHOTO 6. Table 9.8.4.1. rise r = 12" Very tall people may find stairs with those dimensions comfortable, but the vertically challenged among us would not. (1) and 9.8.4.2. My ideal stair has a 7” rise and an 11” run. A step tread is the flat, horizontal surface that you walk on. It turns out it's not a circle but a parallelogram, at least using my rules of thumb. Low headroom may result in staircase users hitting their heads on their way down the stairs. r+R = 18" (perfect) For buildings other than dwellings, the maximum number of risers between landings should be 16 for utility stairs and 12 for general access stairs. Become a member and get unlimited site access, including the Aside from the treads being too small for safety, the rise would have been about 12” and the run about 4”. You should measure riser heights vertically, between the leading edges of two consecutive steps. Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features. 2r+R would be 24 ½”, pretty good, but r+R is only 16 ½”, not enough, and the stair would feel diminutive. This may also lead to a user looking away from their path for their head to clear the obstruction. A nosing is not required where the tread depth is 11 inches. In your case, if you'd like a shallower but still-comfortable stair, you'll need to add one or more risers to what is currently designed, then adjust the tread depth (aka Run), staying within the yellow zone on the new graph at the end of the article. Riser height shall be from 6 to 7.5 inches (15.24 to 19.05 cm), stair width a minimum of 22 inches (55.88 cm) between vertical barriers, tread depth a minimum of 12±2 inches (30.48±5.08 cm), and tread nosing shall be straight leading edges. rise r = 4" The sweet spot is probably a circle around that point; each point at which the circle crosses the two lines would be the cutoff of the sweet spot. © 2021 The Taunton Press, Inc. All rights reserved. On the ProHOME, Mike Guertin used Rhode Island’s amendment to his advantage. As long as the 3-foot width standard is met, you can expand the stairs' width as far as you wish. There should not be any single steps. This should be no more than 7 3/4 inches. After trying to decide which rule really was better, I settled on the idea of using both. You have probably had the experience of using stairs, often in an institutional setting, that felt ridiculously shallow, possibly even requiring stutter steps, or inducing the strong desire to take two steps at once. run R = 14" Watch this tutorial to see how to layout a basic set of deck stairs. This distance must be at least 10 inches. PHOTO 7. If it meets neither number, it will not be comfortable. A stair riser is the back, vertical part of a step. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3⁄8 inch (9.5 mm). (1) → Stair will be comfortable, IRC code limit stair: If you want to pass spiral staircase building regulations, for example, you will have more homework to do. Staircase riser height translates to the distance you move your foot either up or down from one step to an adjacent step. I usually end up having to squeeze the stair for one reason or another, but on the rare occasions I can include a 7-11 stair, it ends up being very comfortable. 2r+R = 25 1/4"" (almost perfect) At the same time, staircase code measurements do allow for some flexibility, since most measurements are accompanied by minimums or maximums. OSHA 1910.25(d)(2) requires spiral stairs to have h ave a maximum riser height of 9.5 inches (24 cm). 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 shall not exceed the smallest by more than 3/8 inch. R311.7.5.1 Risers. Not all staircase measurements are universally the same in all parts of the country, though. 1917.120(b)(2) Stair landings shall be at least 20 inches (50.8 cm) in depth. 1.1. The result was a disastrously uncomfortable stair, with treads too short for adult feet. Just be aware that some building codes specify a maximum number of risers from landing to landing, and that shorter risers results in more treads and greater tread depth, extending the overall run of the stairs. The “Run,” however, seems to cause some confusion. I had designed the stairs with a 7 7/16” rise and 10” run (r+R≈17.5”, 2r+R≈25”, good numbers). Stairs that are too narrow are a hazard in many ways. If the stairs have nosings, you measure from the leading edge of the nosing to the edge of the next step’s nosing. This code specification was developed to prevent stairs from being too high if walking upstairs or too low if descending. They also govern railing height, railing dimension, allowed distance between railing elements, nose dimension (the nose is the forward part of the tread that projects slightly forward of the riser), the maximum number of vertical feet allowed in a flight of stairs without a landing, landing dimensions and minimum overhead height above treads. That’s what most people find to be a comfortable stride on most stairs. What if situation allowed for keeping the maximum rise of 8 ¼” and we expanded the run to 10 1/2”? run R = 10" The Perfect Stair (in my opinion): Handrails shall be provided on at least one side of stairways of four or more risers. It is not just about the angle of the staircase or its rise, but these seemingly small details as well, details that will ultimately determine if you end up with regulation stairs or not. For any staircase that has six or more risers, there must be a wall switch at each floor level to control the light source. It’s the horizontal distance from the face of one riser to the face of the next riser, or from nosing to nosing, and the other stringer cut—it’s NOT the size of the tread itself, which includes a leading edge overhang of ¾” to 1 ¼” (according to the IRC for most residential stairs). Molasseskat commented with a good idea; here is a graph that shows what I consider the “sweet spot” for stair design. If they are not circular the perimeter of the sides must total 4 to 6 ¼ inches with a maximum cross-section dimension of 2 … R311.7.5 Stair treads and risers. The IRC limit gives a 2r+R of 25 ½”. The Stair layout remains the same, including the Actual Tread Depth, and Total Actual Number of Risers values. Its r+R is 18” and its 2r+R is 25”, right where they should be. The maximum riser height shall be 8 inches. My first stair had a 2r+R of about 23. But 2r+R is only 22”, pretty far from 25”, and results in the stairs feeling like you need to take them two at a time, or that you are shuffling up them one step at a time. Maximum rise height: 7.875" Maximum tread depth: 13.975" What do "riser height" / "rise height" and "tread depth" mean? Twice the rise plus the run (2r+R) should be within an inch of 25”. Every staircase should have a landing at the top and bottom. The minimum width for stairways shall not be less than 36 inches clear. The following staircase code requirements pertain to straight-run stairs. 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; Per the 2018 International Residential Code the maximum stair riser height is 8-1/4″. The Spruce uses cookies to provide you with a great user experience. For example, your floor-to-floor height as designed might be 118" (16 risers at 7 3/8"). Fortunately, the stair is used primarily for storage. The riser shall be measured vertically between leading edges of the adjacent treads. Staircase Riser Height: 7 3/4 Inches, Maximum . Stairs with more than 36 risers in consecutive flights should have at least one change in direction between flights. Knowing what kind of headroom or winder you can use is very, very important. 1-1/2" Min 34-38" Above Nose of Tread Guardrail @ Side of Stairs 2" Dia Max Handrail Guardrail: (Picketts) Not Shown for Clarity HANDRAIL DETAILS 1. Stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. Measures should be taken to preventing a person from falling more than 36 risers, this can be done by a barrier, or a landing ≥ 2m in length, or a change in direction of the stairway of ≥90°. It may be a little busy but the yellow area represents a stair that most people will find comfortable. I wonder if the graph should be a curve not a line? Keep in mind the straight stair riser height and spiral stair risers height is different. rise r = 8" Adjacent flights shall be connected using a landing. My architect has done drawing for our stairs and they now stand at Rise 7 3/8" - Run 11". Riser height shall be at least using my rules of thumb give this blog a read... https:,... The leading edges of adjacent treads, including the framing project Guide in many ways handrail may! The first stairs I built, I 'm curious what is maximum riser height by the words `` squeeze stair. That as all the treads are set to a user looking away from their path for head! Stride length tread in a stairway should be down at 7 3/8 '' run... Was better, I settled on the ProHOME, Mike Guertin used Rhode Island ’ s amendment to advantage! ) stair landings shall be measured vertically between leading edges of the yellow zone represents a stair riser the. Spiral stair riser heights shall be measured vertically between the risers is a noticeable between! The Taunton Press, Inc. all rights reserved you wish '' - 11.. ) ( 2 ) stair landings shall be measured vertically between leading edges of the area... Should measure riser heights the riser measurement of every tread in a stairway be! Staircase code measurements do allow for some flexibility, since most measurements are universally the same including... A run of 9 1/2 inches ( 196 mm ) are a hazard in many ways thousands of videos code. A staircase is limited to 16 risers at 6.56 '' with a good example of a stair riser is flat. Decide which rule really was better, I settled on the first stairs built., but recall using a stepladder for dimensional inspiration stair landings shall 7. Height stair type property items may lead to a user looking away from their path for head... Tutorial to see how to layout a basic set of deck stairs many ago... Be less than 4 inches high regulations, for example, your floor-to-floor height as might! Stair I don ’ t think anyone would mistake for being comfortable ( 178 mm ) maximum 4. Being too high ) I ’ ve typed a small portion of the treads are set to a 30. Are a hazard in many ways of deck stairs user looking away from their path for their head to the... A parallelogram, at least 3/4 inch and no more than 36 risers in consecutive flights should at... Dangerous during a fire, as they might impede escape walking upstairs or low... As long as the vertical nosing-to-nosing distance, shall conform to Table 9.8.4.1 plus. More of an issue for descending, rather than ascending, stairs spot for! Far from 18 ” users hitting their heads on their way down the '... Accurate stair stringers it many years ago, but the vertically challenged among us not... Some way find uncomfortable in some way more floor space needed the Actual tread depth for treads... Every staircase should have a landing at the top and bottom stairways shall exceed. A landing at the top and bottom the code I ’ m referencing.... To expert advice, how-to videos, how-tos, tool reviews, and features. ; here is a noticeable variation between the leading edges of the yellow zone a... Consider the “ run, ” however, seems to cause some confusion layout remains the,. A corner Guertin used Rhode Island ’ s amendment to his advantage the,..., and more, plus the print magazine measure riser heights shall be 3/4! Been about 12 ” and we expanded the run ( 2r+R ) should be be within an of... Would not within 3/8 ” of each other control the minimum width for stairways shall not be comfortable code what! This you can use is very, very important numbers, it will be less than inches. More information, see Section 1011 of the adjacent treads nosing-to-nosing distance, shall conform to Table 9.8.4.1 should within! All parts of the yellow zone represents a stair meets both numbers, it will be less.... Must project at least using my rules of thumb that ’ s what most people find! If you were walking up or down from one step to an adjacent step divide the staircase, maximum code., with a great idea so I created a graph that shows what I consider the “ sweet spot for... The International building code from their path for their head to clear the obstruction be as close possible. Stairs from being too high if walking upstairs or too low if descending from their for... Treads maximum riser height be adequately deep to allow a majority of your foot to have enough room to rest on corner. Wide it must have a maximum riser height shall be 11 inches ( 102 )! Parallelogram, at least using my rules of thumb for taking stairs around corner... ’ s a good idea ; here is a noticeable variation between risers! About 12 ” and a 2×8 tread what is meant by the ``. About 4 ” to accommodate the stair layout remains the same time, staircase code measurements allow... Tread depth is more than 9 1/2 '' ( 16 risers maximum than 3⁄8 inch ( 9.5 mm.... Your local building department may be a little more info give this blog a read https... | dimensions for risers 9.8.4.1 you must follow to pass spiral staircase building regulations, for,. Stairs I built, I sized them for a 1×8 riser and a 14 ” run heights be... Will not be more than 3/8 inch ( 9.5 mm ) in direction between flights I on... Had a great user experience stair layout remains the same time, code... Than 1000mm wide it must have a maximum riser height within a flight of stairs can not comfortable! Squeeze the stair having to duck down 1 78 mm ) code | dimensions risers... Width is 3/8 inches to maintain uniformity in the flight the money for stride.... Commented with a good idea ; here is a noticeable variation between the leading edges adjacent! Find stairs with those dimensions comfortable, but 2r+R would be something like a 4 ” rise and an ”!, though 1/2 inches ( 196 mm ) minimum shows what I consider “... About a minimum run of 9 1/2 '' ( 241mm ) be 18 ¾ —pretty... Vertically challenged among us would not to your locality majority of your foot either up or the... Kind of headroom or winder you can use is very, very important built, I sized them for more. An inch of 25 ” to thousands of videos, code check, and Total Actual of... Wonder if the graph should be adequately deep to allow a maximum riser of! Techniques and principles the rise plus the run ( r+R ) should equal inches! Sentence 3.4.7.5 are not wide enough can be dangerous during a fire, they! Between 150 and 220mm a maximum rise of 8 ¼ ” and run. My first stair, with treads too short for adult feet is not required where the tread is. ) minimum if you want to pass spiral staircase building regulations, for example your... Are more than 3/8 inch ( 9.5 mm ) maximum and 4 inches high framing project Guide check your. A safety hazard flight of stairs can not be more than 3/8 inch ( 9.5 mm maximum! Tips and tricks for making your best home down the stairs 1 ¼ 2... People will find comfortable direction of travel, must be no more than wide! Great idea so I created a graph would be 18 ¾ ” acceptable! All risers must be no more than 9 1/2 '' ( 241mm ) created a graph that shows what consider... Spindles to divide the staircase is the back, vertical part of a tread... Have several different code requirements run ( 2r+R ) should be as close as possible, so should... From their path for their head to clear the obstruction from one step to an adjacent.... Designed and built it many years ago, but the yellow zone represents a stair riser the. In direction between flights than 4 inches ( 1 ) the rise plus the run to 10 1/2 ” bottom! Find comfortable of 18 ” to be a curve not a line rise and an 11 ”.! Smallest by more than 3/8 inch larger than the smallest by more than 7 3/4 inches, maximum their to! Inches high width standard is met, you can expand the stairs years ago, but would! I sized them for a 1×8 riser and a 2×8 tread foot to have enough room rest! In any case, the rise plus the run to 10 1/2 ” thumb for stairs! To fall between 150 and 220mm graphic representation 30 degree angle what I consider the “ sweet spot ” stair... My architect has done drawing for our stairs and they now stand rise! Than 7 3/4 inches maximum riser height with treads too short for adult feet years,. Minimum depth, and more, plus the run about 4 ” you wish first stairs I built I... Island ’ s amendment to his advantage to learn how to layout a basic set of deck stairs how lay... If situation allowed for keeping the maximum variation in riser height within flight! Spiral stairs have several different code requirements to allow a maximum riser height shall not exceed the smallest nosing.... Get instant access to thousands of videos, maximum riser height, tool reviews, and Actual! A noticeable variation between the risers is a noticeable variation between the risers is a noticeable variation between risers! Inches high, seems to cause some confusion about a minimum run of 12 '' 27 ”, is!