For example, the minimum hand clearance between the railing and the wall that it is mounted on is 1 1/2 inches. In other words, the space must be slightly less than 4 inches high. A 5-foot diameter or larger stair will provide this standard stair width; Stair tread codes states that each tread will have a minimum of 7 1/2 inch tread depth at 12 inches from the narrow edge; All treads will be identical The width must continue up to the minimum headroom of 80 inches above the tread or landing surface. The 12-inch (305 mm) dimension shall be measured from the widest point of the clear stair width at the walking surface of the winder. See the Life Safety Code . Public): 44” | 112 cm2 People: 49” | 125 cm2 People (Comfortable): 60” | 152 cm3 People: 74” | 188 cmHuman Body Accommodation: 22” | 56 cm, Drawings include:Stair Widths front elevations, front (people). Be sure to check with your permitting agency about building codes that apply to your locality. Exception #2: Clear width of 48” not required in building sprinkled throughout. Comfortable two person stair widths range between 49” (125 cm) to 60” (152 cm). Minimum clear walking path of 26 inches. (3) Riser height and tread depth shall be uniform within each flight of stairs, including any foundation structure used as one or more treads of the stairs. Florida Building Code, Residential. Stair treads shall be no less than 11 in (280 mm) wide, measured from riser to riser. Where winders are adjacent within the flight, the point of the widest clear stair width of the adjacent winders shall be used. Anyone walking up or down the stairs should have plenty of clear headroom without having to duck down. However, the very minimum width between handrails is 44 inches. The nosing shall project no more than 1-1/2 inches (38 mm). Be careful to note that some sections of stair railing code work in conjunction with other sections of stair code. Fixed stairways shall have a minimum width of 22 inches. The nosing on treads, believe it or not, has a code minimum and maximum of how far the nosing projects over the next stair. For any staircase that has six or more risers, there must be a wall switch at each floor level to control the light source. Use our Size Comparison calculator to compare the dimensional properties of Stair Widths with other related elements from our database. The greatest tread depth within a flight of stairs cannot be more than 3/8 inch larger than the smallest tread depth. at or below handrail height on each side . width difference is 3/8” based on all treads) The greatest riser height within a flight of stairs cannot exceed the smallest by more than 3/8 inch. But, this rule includes a phrase that states that its only for the required width. Not all staircase measurements are universally the same in all parts of the country, though. 4.9.3 Nosings. Interior stairs shall be at least forty-four inches wide except as follows: International Building Code for Stair treads and risers 1009.3 Stair treads and risers. and 50 deg. to a maximum of 1-¼-in. The rule is that you are supposed to be within 30″ of a handrail at any point on the stair, so you see intermediate handrails in wide stairs for this purpose. "Stair width." A 5-foot diameter or larger stair will provide this standard stair width; Stair tread codes states that each tread will have a minimum of 7 1/2 inch tread depth at 12 inches from the narrow edge; All treads will be identical Maximum 4-1/2 inch handrail projection into stairway width, on either side. If under 50 occupants you can go to 36″ width. Stair Building Code Requirement Highlights. A comprehensive reference database of dimensioned drawings documenting the standard measurements and sizes of the everyday objects and spaces that make up our world. Any uniform combination of rise/tread dimensions may be used that will result in a stairway at an angle to the horizontal within the permissible range. Stairway landings and platforms are at least the width of the stair and at least 30 inches (76 cm) in depth, as measured in the direction of travel; 1910.25 (b) (5) When a door or a gate opens directly on a stairway, a platform is provided, and the swing of the door or gate … Staircase code states that stairs must be 3 feet wide or wider. Select an item on the right to compare relative dimensions to Stair Widths. 1910.24(e) "Angle of stairway rise." 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. 3DM, OBJ, SKP formats, Dimensions is a project by Fantastic Offense. Stair tread depths shall be 11 inches (279 mm) minimum. BS5395-1 Stairs ladders and walkways. Marking stripes shall have a width of at least 1 inch (25 mm) but not more than 2 inches (51 mm). The Codes (2009 IRC): 311.7.1 – Stairways shall be a minimum of 36” wide 311.7.4.1 – Maximum Riser Height is 7 ¾” (max. Staircases must be designed to allow safe access, escape and fire rescue access and the minimum requirements for these elements are covered by the Building Regulations. Stair widths are based on the use and occupancy loads of adjacent spaces and must be serviced with handrails on one or both sides depending on the stair width.Consult the building code for details on specific occupancy loads. 27.3 NOSINGS The undersides of nosings shall not be abrupt. You must calculate the IBC stair width for multi-story stairways versus single-story stairways. So what is the minimum staircase width required in an apartment block? There is currently no specified minimum width in the Building Code. Stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. I'm thinking my home builder has sized my stairs too narrow to meet code, but he disagrees. Most stairs are between 900mm – 1100mm wide, for comfortable use. At this point a landing must be provided which will have a length at least the same as the width of the steps leading up to it. However, the minimum clear width of the stairway from the riser to the handrail must be at least 31.5 inches for one handrail, and 27 inches for two handrails. Thus it varies by state and town. All stairs are required to comply with the following: 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. This code specification was developed to prevent stairs from being too high if walking upstairs or too low if descending. This distance must be at least 10 inches. In any case, the local code is what you must follow to pass inspections. Stairs, stairways, staircases, or stairwells, are building components that provide users with a means of vertical movement with the distribution of separate and individual vertical steps. The Ontario Building Code | Dimensions for Risers 9.8.4.1. By using The Spruce, you accept our, Staircase Riser Height: 7 3/4 Inches, Maximum, Staircase Tread (Run) Depth: 10 to 11 Inches, Minimum, Staircase Headroom: 6 Feet, 8 Inches, Minimum, Deck Code Guidelines for Guardrails and Stairway Railings, Stone Steps vs. Normal fire and building codes restrict the rise of stairs to not more than 12 feet. Imagine having a 12’ high stair in place with a riser height of 9” and a tread depth of 9”. The IRC 2018 Residential Code with amendments was used For three simultaneous users, a minimum of 74” (188 cm) is recommended. Code (below) requires minimum 36-inch width above handrail and below headroom height. 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. Staircase riser height translates to the distance you move your foot either up or down from one step to an adjacent step. The pitch angle should not be less than 26.5 degrees, and not greater than 45 degrees. The largest nosing projection cannot be more than 3/8 inch greater than the smallest nosing projection. My stairs have a baseboard on each side of the stairs (1/2" thick), and stair width measurement is 35" at tread (baseboard-to-baseboard), however, a few inches above the baseboard, the stair width measures 36" (paint-to-paint). Open risers are not permitted. These rules are aimed at making staircases as safe as possible, so they should never be ignored or bypassed. This stair would have (16) treads, 9”deep for a total run of 11’3”. The width of the landing, measured perpendicular to the direction of travel, must be no less than the width of the staircase. So if the stair only has to be 36″ wide and they make it 96″ wide, the handrails at the edges are sufficient. Stairways shall be not less than 36 inches (914 mm) in clear width at all points above the permitted handrail height and below the required headroom height. Width = 0.3 x floor’s occupant load Headroom (IBC 1011.3) Stairways are required to have a headroom clearance of 80 inches from the edge of each stair nosing measured vertically up to the ceiling. As long as the 3-foot width standard is met, you can expand the stairs' width as far as you wish. except projections not more than 114 mm (4½ in.) For stairs serving a single user (typically private residential), a minimum of 36” (91 cm) is required. Concrete Steps in Gardens. All staircases with four or more risers require at least one handrail, which can project up to 4.5 inches on either side of the stairway. Low headroom may result in staircase users hitting their heads on their way down the stairs. Our team is familiar with the technical requirements of stairs and will be happy to assist with your query. Doors opening onto a landing shall not reduce the landing to less than one-half the required width. Exit stair treads shall incorporate a marking stripe that is applied as a paint/ coating or be a material that is integral with the nosing of each step. 311.7.4.2 – Minimum Tread Depth is 10” (max . The center of the winder tread is always going to be greater than 10 inches if the stairs are 36 inches wide. Handrails must be placed every 60” (152 cm). Therefore, a stair with a projection on one or both sides must provide a minimum clearance width of 760 mm (860 mm – 100 mm). Clear openings of doorways with swinging doors shall be measured between the face of the door and the stop, with the door open 90 degrees (1.57 rad). Stairs, stairways, staircases, or stairwells, are building components that provide users with a means of vertical movement with the distribution of separate and individual vertical steps. Would you allow the minimum 36” Stair width based on occupant load of 41 persons per stairway? In short, the width is calculated by multiplying the occupant load served by such stairs by a factor of 0.3 inch per occupant. (1) Stairways serving an occupant load of more than 50 shall be not less in width than 44 inches. 6 ft. 8 in. Nosings are required to overhang a minimum of ¾-in. 3)Required exit stairs and public stairs serving buildings of other than residential occupancy shall have a width of not less than the greater of a) 900 mm, or b) 8 mm per person based … Measured nosing to nosing. Stairways shall not be less than 36 inches (914 mm) in clear width at all points above the permitted handrail height and below the required headroom height PHOTO 1. Get daily tips and tricks for making your best home. Australian Standard 1657 – 4.1 – Angle And Width Of A Stair’s Slope Regarding the width and angle of the slope, stairways shall not be less than 600 mm wide measured between the edges of the safety handrails. This becomes an issue when stairs are installed in tight locations under codes that vary greatly from today’s current International Building Code (IBC) variants. ©2020 Dimensions.com | All rights reserved. Width. No interior stair shall be reduced in width in the direction of exit travel. If winders are adjacent within the flight, the point of the widest clear stair width of the adjacent winders shall be used. Measurement of Clear Height over Stairs – Parts 3 and 9 - slide 1; Measurement of Clear Height over Stairs – Parts 3 and 9 - slide 2 ; Measurement of Clear Height over Stairs – Parts 3 and 9 - slide 3; Minimum Clear Height over Stairs, Ramps and Landings – Part 3 - slide 1; Minimum Clear Height over Stairs, Ramps and Landings – Part 3 - slide 2; Minimum Clear Height over Stairs, Ramp Stairways have to be at least 44″ if you have an occupant load over 50 (and may be more if your occupant load is large). stair treads. Stair width is defined as the clear width of the stair tread used as the walking surface. Join our monthly newsletter! Or call us with your query on 0800 896 500. Updated daily. Our team is familiar with the technical requirements of stairs and will be happy to assist with your query. For stairs serving one floor, multiply the floor’s occupant load by 0.3. Scaled 2D drawings and 3D models available for download. Private stairways serving an occupant load of less than 10 may be 30 inches wide. However, if the steps do not have nosings, and the steps have solid risers, not open risers, the minimum tread depth is 11 inches. Minimum width below handrail is 31-1/2-inches. Therefore, a stair with a projection on one or both sides must provide a minimum clearance width of 760 mm (860 mm – 100 mm). Private stairways shall be a minimum of thirty-six inches wide. Private stairways serving an occupant load of less than 10 may be 30 inches wide. Minimum clear walking path of 26 inches. Stair Building Code Requirement Highlights. Staircases must be firmly fastened to the building. (2) At least one stair between each floor level within a dwelling unit, and exterior stairs and required exitstairs serving a single dwelling unit, shall have a width of not less than 860 mm. In general public spaces a minimum of 44” (112 cm) must be met—providing ample space for one person and allowing the tight passage of two people. R311.7.1 Width Stairways shall be not less than 36 inches (914 mm) in clear width at all points above the permitted handrail height and below the required headroom height. Dimensions for Risers (1) The ... service stairs are stairs that serve areas used only as service rooms or service spaces and stairs that serve mezzanines not exceeding 20 m 2 within live/work units. Stairways shall be not less than 36 inches (914 mm) in clear width at all points above the permitted handrail height and below the required headroom height. Section 1011.2 Minimum width shall be not less than 44”. Nosing. … Recent building code revisions have reduced the openings between balusters to not larger than 4 inches. open side of stairs to be 34” as measured from the nose of the stair treads. Code of practice for the design, construction and maintenance of straight stairs and winders. The 12-inch (305 mm) dimension shall be measured from the widest point of the clear stair width at the walking surface of the winder. (1) Except as provided in Sentence (2), required exit stairs and public stairs serving buildings of residential occupancy shall have a width, measured between wall faces or guards, of not less than 900 mm. Building codes mandate stairs should be at least 36 inches wide. There are other exceptions for spiral stairs, aisle stairs and incline stairs but these types will have to be covered in a later post. Stairways serving an occupant load of 50 or less may be 36 inches wide. 12 ft. The minimum depth, measured in the direction of travel, is 36 inches. (2) Trim shall not reduce the required width by more than 3 1/2 inches. It is by no means all-inclusive or has all code related sections listed. (2) If the required width of a ramp or f light of stairs is more than 2 200 mm, one or more intermediate handrail s continuous between landings shall be provided, and located so that there will be not more than 1 650 mm between handrail s. (3) handrail s shall be continuously graspable along their … The Stairs- Residential Building Code for the U.S. is a municipal regulation. 2) Doublestair-width platforms, or single- stair-width platforms with adjacent- passageways, shall be a minimum of 50 inches wide. Stairs that are too narrow are a hazard in many ways. You can check current stair regulations in full here (PDF). From the top flight of stairs to the bottom of the stairs, each individual riser cannot exceed a difference of 3/8 of an inch. The "nosing," or overhang of a step over its riser, cannot be more than 3/4-inch in width. 36 in. The width shall not be less than specified elsewhere in this code. discrepancy is allowed) The reason for the codes? This width is great for three winders to make a turn of 90 degrees. As long as the 3-foot width standard is met, you can expand the stairs' width as far as you wish. Nosing. But we point out that in general, the minimum recommended stair width is between 34" and 36" Across the width of the tread. Knox County Code Administration & Inspection 2018 IRC Residential Stairs Information 2018 IRC Section R311.7.8 HANDRAILS R311.7.8 Handrails. This means each winder stair creates a 30-degree angle. Rev 022019 GUARDRAILS HANDRAILS Handrail Wall H 1 ½” min. In a building setting, a flight of stairs refers to a complete series of steps that connects between two distinct floors. 9 in. Introducing "One Thing": A New Video Series, The Spruce Gardening & Plant Care Review Board, The Spruce Renovations and Repair Review Board. Nosings must project at least 3/4 inch and no more than 1 1/4 inches beyond the riser below. We created this guide to help stair designers navigate through the complexity. The total width of means of egress in inches (mm) shall not be less than the total occupant load served by the means of egress multiplied by 0.3 inches (7.62 mm) per occupant for stairways and by 0.2 inches (5.08 mm) per occupant for other egress components. 1 Person (Private): 36” | 91 cm1-2 People (Min. Is it Hard to Make Winder Stairs? to a maximum of 1-¼-in. Summary of Code Requirements for Residential Stairs. 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. Maximum Height of Risers . Variations in riser height or tread depth shall not be over 1/4-inch (0.6 cm) on any stairway. Most stairs are between 900mm – 1100mm wide, for comfortable use. Regulated by building codes, stair details specify the sizes of risers and treads, stair widths, the placement of handrails and guardrails, and construction methods for fabricating stairs. Many communities adopt the International Building Code wholesale, while others make modifications. HOME HARDWOOD STAIRS Hardwood Stairs: Residential Building Codes, US: Stairs Residential Building Code for the United States. Provides the code requirements for the width of stairs, riser and run height, and nosing extension when buidling stairs. Therefore let us recap on the residential stair code requirements: Minimum 36 inch clear width for stairway. This distance must be at least 36 inches and does not include handrails. A prime example is the standard stair width. BS5395-1 Stairs ladders and walkways. Imagine having a 12’ high stair in place with a riser height of 9” and a tread depth of 9”. Code of practice for the design, construction and maintenance of straight stairs and winders. The Spruce uses cookies to provide you with a great user experience. Staircase measurements are determined by common practice and by building code, which itself is often informed by generally approved practices. Using toenails or nails to attach the stairs is prohibited because the weight of people using the stairs might cause these fasteners to be pulled loose. The radius of curvature at the leading edge of the tread shall be no greater than ½ inch (½" = 13mm). Each stair tread is 11 inches (280 mm) deep minimum with a sloped riser. Landing . Stairway landings and platforms are at least the width of the stair and at least 30 inches (76 cm) in depth, as measured in the direction of travel; 1910.25 (b) (5) When a door or a gate opens directly on a stairway, a platform is provided, and the swing of the door or gate … 3) Platform lengths shall be a minimum of 36 inches where exits do not open onto platforms. 7.2.2.5.5.1 Exit Stair Treads. (2) Stairways. Maximum Height Between Landings . §1011.2 Thus it varies by state and town. This guide will teach you about: All the different stair codes and stair regulatory agencies; How the different stair codes and standards relate to each other The Stairs- Residential Building Code for the U.S. is a municipal regulation. On any given flight of stairs, all steps shall have uniform riser heights and uniform tread widths. The marking stripe shall be installed along the horizontal leading edge of the step and shall extend the full width of the step. The number of occupants on each floor will determine the required width of the stairs. The following staircase code requirements pertain to straight-run stairs. A stair riser is the back, vertical part of a step. (2) Stairs shall be installed between 30o and 50o from horizontal. All clinical staff shall have the keys, codes or other means necessary to operate the locking devices. Comfortable two person stair widths range between 49” (125 cm) to 60” (152 cm). This becomes an issue when stairs are installed in tight locations under codes that vary greatly from today’s current International Building Code (IBC) variants. The minimum recommended stair landing length is 36" (or a length and width sufficiently greater than the swing of the door if … R311.7.1 Width. For stairs serving a single user (typically private residential), a minimum of 36” (91 cm) is required. From the top flight of stairs to the bottom of the stairs, each individual riser cannot exceed a difference of 3/8 of an inch. Narrow stairs make it more difficult to carry items up and down the stairs. 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. In a building setting, a flight of stairs refers to a complete series of steps that connects between two distinct floors. IBC Stair Width Calculation Calculating the IBC stair width can be complicated because it is determined by the building’s occupant load, so we have put together this simplified version of the IBC codes. At the same time, staircase code measurements do allow for some flexibility, since most measurements are accompanied by minimums or maximums. 1) Single-stair-width platforms shall be a minimum of 40 inches wide. The nosing on treads, believe it or not, has a code minimum and maximum of how far the nosing projects over the next stair. Be careful to note that some sections of stair railing code work in conjunction with other sections of stair code. The minimum recommended stair width is between 34" and 36" ACROSS. Vermont Department of Public Safety . This should be no more than 7 3/4 inches. Additionally, the riser measurement of all of the treads should be as close as possible to identical. This is plenty safe. Note that handrails and constructions below handrails are not allowed to project more than 100 mm into the required stair width (X + Y ≤ 100 mm). Maximum height is 38”. The stair provisions of 7.2.2.2.1.2 require extra stair width for buildings, such as this high-rise building, where it is expected that occupants will still be in the process of leaving the building when emergency responders such as fire fighters arrive. See Fig. A step tread is the flat, horizontal surface that you walk on. This may also lead to a user looking away from their path for their head to clear the obstruction. 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. (1) Stairways serving an occupant load of more than 50 shall be not less in width than 44 inches. HOME HARDWOOD STAIRS Hardwood Stairs: Residential Building Codes, US: Stairs Residential Building Code for the United States. Minimum width clear of all obstructions . The minimum recommended stair landing length is 36" (or a length and width sufficiently greater than the swing of the door if … Minimum Tread Depth. Stair tread depth is more of an issue for descending, rather than ascending, stairs. There is currently no specified minimum width in the Building Code. Stairways serving an occupant load of 50 or less may be 36 inches wide. The width of interior stairs shall be the clear width between walls, grilles, guards, or newel posts. Too low if descending long as the walking surface full width of.. This guide to help stair designers navigate through the complexity to riser single. 9 ” between 30o and 50o from horizontal are too narrow are a hazard in ways... May not encroach into this minimum width of the landings shall be not less in width than 44.... Riser, can not be more than 3 1/2 inches a tread depth is ”. 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Has all code related sections listed the smallest tread depth is 10 ” ( max designers navigate stair width code complexity! 1/4 inches beyond the riser below of thirty-six inches wide for making your best home complex!