Summary of Ideal Stair Dimensions for Closed Riser Stairs
- Stair riser height: ideal: 7 3/4 Some older homes include a very steep stairway to access the home's attic. ...
- Stair tread nosing: required, 1" to 1 1/2" projection beyond the riser face
- Stair tread run (or horizontal depth): 8 1/4 to 9" or no less than 10" per the U.S. IRC.
- Stair tread thickness: 1" or greater, tread is supported by the riser.
What is the standard height for a stair riser?
The code specifies that risers should not be more than 7 ¾ inches in height and that any variation of risers within a flight of stairs should not be more than ⅜ inch. Note that dimensions here should be taken excluding carpets, rugs, or runners.
What is the maximum height of a stair?
The height limit established by code is intended to provide a reasonable interval for the user so that they may rest on a level surface and to alleviate the negative effects of long uninterrupted flights. The code establishes a maximum vertical height of 151 inches (12 feet 7 inches) between landings or floor levels for a flight of stairs.
What is the ideal stair rise?
On the other hand, a stair that is 5 inches high and 13 inches long might be acceptable, according to building safety suggestions. The total of the rise plus the run is 18, which meets the ideal, according to the first rule. But it would be slightly uncomfortable based on the second rule, given that double the rise plus the run equals 23.
What is the minimum tread depth for stairs?
The tread depth code for residential stairs should be no less than 10 inches with nosing, no less than 11 inches without nosing, and maximum tread depth variation should also be less than 3/8 of an inch. How deep is a step? The depth (also called tread or run) of each step should be a minimum of 10 or 11 inches depending on the type of stairs.
What is a normal stair riser height?
Riser Heights In the United States, the step height standard should be between 7 or 7 ¾ inches at the most, and no less than 4 inches. You should follow other measurements if given by local building codes. In Canada, the maximum step riser height is 8 ¼ inches.
What is a comfortable riser height?
Over the years, carpenters have determined that tread width times riser height should equal somewhere between 72 to 75 inches. On a main stair, the maximum rise should be no more than 8 1/4 inches and the minimum run should be no less than 9 inches.
Can stair risers be 8 inches?
The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3/8 inch. 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 inch minimum run.
What is the ideal tread to riser ratio?
An “ideal” ratio is 7 in. rise and 10 in. tread. These dimensions may vary slightly if the rise and/or run of a stairway must be held within certain limits.
Is an 8 inch step too high?
Building codes in many areas define maximum step height and minimum tread width, but in areas where it is not defined, Council of American Building Officials and International Code Council both recommend the rise to be no more than 7.75 inches and runs to be no less than 10 inches.
How many steps is a 4 foot rise?
Use your minimum riser height; if you roundup, this would push the riser under the minimum limit. In Edmonton, the minimum is five inches. Nine rises (round down) with eight steps (minus one). A four-foot high deck can have a range between 6 and 8 steps.
What is the standard for stair treads and risers?
Stair Treads Stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. Stair tread depths shall be 11 inches (279 mm) minimum. The riser height shall be measured vertically between the leading edges of adjacent treads.
Do stair risers go on top of treads?
When installing stairs, install the riser first, and then the tread. Start at the bottom of the stairs and work your way up, alternating risers and treads. The back of each tread will sit flush against the riser. Treads and risers fasten with construction adhesive to the subfloor.
How many steps before a landing is required?
12 stepsHow many steps require a landing? For general access stairs a maximum allowance of 12 steps before a landing is required. With utility stairs, a maximum of 16 steps is allowed before a landing.
How do I calculate rise in stairs?
Determining the Rise You divide the height by 7 inches; if, say, the floor-to-floor distance is 8 feet, 10 inches (or 106 inches), then you'll need 15 treads (106 divided by 7 equals 15.14).
What is the best angle for staircase?
around 37°Stair codes and guidelines prefer an angle of around 37° for normal stairways (the green area in our illustration) and around 7° for ramps (the yellow area in our illustration). Steeper slopes or angles are permitted for stepladders in certain applications as you can see in the illustration.
How do you calculate riser?
To determine the number of risers in the staircase take the total height between floors, in inches, and divide by 8.25. We use 8.25 in this example because New York State Code lim- its the maximum height of a riser to 8.25 inches.
What is a comfortable stair angle?
Stair codes and guidelines prefer an angle of around 37° for normal stairways (the green area in our illustration) and around 7° for ramps (the yellow area in our illustration). Steeper slopes or angles are permitted for stepladders in certain applications as you can see in the illustration.
What is the standard rise and run for deck stairs?
The maximum allowable stair rise is 7 3/4 inches, and the minimum stair rise is 4 inches. For recommendations on rise-run combos, see the tip below. The difference between a stair's longest and shortest riser height or stair depth should be no more than 3/8 inch.
Where is the riser on a stair?
OSHA 1910.21 defines a stair riser as the upright (vertical) or inclined member of a stair that is located at the back of a stair tread or platform and connects close to the front edge of the next higher tread, platform, or landing. According to IBC 1011.5.2, the riser height is measured vertically between the nosings (the leading edge) ...
How high should ship stairs be?
OSHA 1910.25 (e) (2) requires ship stairs to h ave open risers with a vertical rise between tread surfaces of 6.5 to 12 inches (17 to 30 cm).
How high should a tread be for alternating tread stairs?
For treads and riser of alternating tread stairs, OSHA requires that alternating tread stairs have a series of treads installed at a slope of 50 to 70 degrees from the horizontal and that they have a minimum tread depth of 8.5 inches (22 cm).
What is the minimum tread depth for a standard stair?
OSHA 1910.25 (c) (3) requires standard stairs to h ave a minimum tread depth of 9.5 inches (24 cm). IBC 1011.5.2 requires that stair treads be 11 inches ...
What is the stair tread code?
Under OSHA 1910.21 the stair tread means a horizontal member of a stair or stairway, but does not include landings or platforms. IBC 2018 states that "tread depth is measured horizontally between the vertical planes ...
Why do ship stairs have less tread depth?
Generally, steeper angled stairs, like ship stairs or ships ladders, have less tread depth because as a stair gets steeper, the tread above becomes an obstacle to the tread below.
How deep is a ship ladder?
OSHA 1910.25 (e) (3) requires ship stairs to h ave minimum tread depth of 4 inches (10 cm).
How much should a stair rise be?
The total length of the stair rise plus the run (r+R) should equal around 18 inches with no more than a 1-inch deviation. Also, twice the rise plus the run (2r+R) should be equal to 25 inches, also with a 1-inch deviation.
How tall is a standard stair?
On average, American architects have used a standard stair height of 7.5 inches. On stairs built inside, the average step length is 9 inches tall, while outside steps have an average length of 11 inches tall. Advertisement. Although not the current average, one study by the National Library of Medicine looked a small deviation between stair heights ...
How tall should a stair tread be?
Researchers found that the ideal step height is 7.2 inches and the ideal tread width should be anywhere between 11 and 12 inches.
How to determine stairway run?
There are two calculations that can help determine whether a stairway's rise and run will feel comfortable during use. The total length of the tread rise plus the width—or run— (r+R) should equal around 18 inches with no more than a 1-inch deviation. Also, twice the rise plus the run (2r+R) should be equal to 25 inches, also with a 1-inch deviation.
How much space does a staircase take up?
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. Not all houses have space for those extra 3 feet of stairs, so the amount of floor space a stairway can take up also needs ...
How tall should a step be?
Researchers found that the ideal step height is 7.2 inches and the ideal step length should be anywhere between 11 and 12 inches. Building codes in many areas define maximum step height and minimum step length, but in areas where it is not defined, Council of American Building Officials and International Code Council both recommend ...
What is the total of the rise plus the run?
The total of the rise plus the run is 18, which meets the ideal, according to the first rule. But it would be slightly uncomfortable based on the second rule, given that double the rise plus the run equals 23. A more ideal step that is 7 inches tall with an 11-inch run gives a total run plus rise sum of 18 and a total double rise plus run sum ...
How tall should a stair riser be?
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.
How much slope does a step riser have?
Step riser slope out of vertical: <= 30 deg measured from horizontal surface of the tread
What is the thickness of stair tread?
Stair tread thickness: 1" or greater; tread is supported by the riser.
What should stairway handrails be?
Stairway handrailings should be continuous, graspable, and enclosed at ends
How many treads are needed for a riser?
The sum of two treads plus one riser should add up to around 28" or 29"
How long is a stair landing?
Minimum recommended stair landing length: 36" in the direction of travel
What is an ideal stairway?
By "ideal stairway" we mean a stair that complies with building codes and recommended stair construction standards and that produce a stair that is comfortable to climb or descend.
How many risers are required on a flight of stairs?
Each flight of stairs having four or more risers must be provided with handrails on not less than one side.
How wide should a stairway be?
The minimum width for stairways shall not be less than 36 inches clear. Now when handrails are introduced they shall not project more than 4 ½ inches on either side. Therefore if a handrail is provided on one side, the clear width of the stairs shall not be less than 31 ½ inches and when handrails are provided on both sides, ...
How deep should stair treads be?
Stair Tread Depth. As for stair treads the depth should not be less than 10 inches however this will require nosing projections. To avoid having to install nosing the code requires the depth of the tread to be no less than 11 inches.
Why should stair treads be within the parameters of the code?
Stair riser heights and stair tread depths should be within the parameters of the code to avoid any potential trip hazards for inconsistencies. A uniform flight of stairs provides a safety factor. Inconsistencies or variations in risers or treads could interfere with the rhythm of the individual using the stairs. Therefore limitations in riser heights and minimum widths for treads is an important rule to follow.
What is the difference between a Type I and Type II handrail?
Type I handrails layout the parameters for handrails having a perimeter dimension not greater than 6 ¼ inches while Type II handrails address handrail perimeters greater than 6 ¼ inches.
What is the IRC code for stairs?
When it comes to residential stair standards, the International Residential Code (IRC) establishes minimum requirements for stairs to insure a level of safety to the public. Several components are looked at such as stair width, headroom, riser and tread heights.
What type of handrails are recognized by the code?
When it comes to handrails the code is very specific on this. It should provide proper graspability which the code recognizes a Type I and Type II handrail to have.
How much difference between threads on stairs?
Regarding the comments made about having 3/8 of a difference from any two threads, I've always thought and worked believing you were allowed 3/16 max difference from one thread to the next. If your differences between all the threads over the whole stairs added up to more than 3/8 then the stairs could fail. So if you had 1/16 difference on each rise over seven rises the stairs could fail. Anyway, take your time marking the stringers level and plumb. As someone said earlier don't be afraid of the circular saw, worst case you cut too much and need to shim the thread. Building a stair can be very satisfying but trying to fix someone else’s mistakes can be frustrating. Just go for it.
Can you use a circular saw to cut stairs?
Drywall is attached to the bottom side of the stringers to make up a ceiling underneath the staircase, making it impossible to use a circular saw to cut the treads. Currently, new stringers are not an option.
Do you shim and glue risers?
When you install your new treads and risers you will shim and glue anyway, so any imperfections in your cut will be removed. If you can, talk to your supplier and get a tongue and groove tread/riser combination. Rip your risers to their proper height. That will also make your job much easier for the installation.
Can I use 3 piece plywood for stringers?
Only use dry, well machined wood for this blocking, or what I've done lately is glue 3 pieces of 3/4" exterior grade plywood and cut new stringers and PL/nail them in place. I typically use 3 piece glueups for outer stringers and 2 piece glue ups on either side of the middle stringer. After everything is installed (lots of PL - as stated, it will take up any minor imperfections/bridge small gaps), it feels like you're walking on concrete stairs!
Can you trim rough stringers with a router?
Also, in my experience, a lot of the time the rough stringers are bowed/twisted/warped out of plumb, which makes it that much more difficult to trim with a router. The cut will be clean but it will be perpendicular to the stringer face, which, if it is not plumb, will result in an out of level tread cut.
How many inches does a stair tread need to run?
Run Requirements. The “run” is the measurement of the tread, which needs to be a minimum of 10 inches if the tread has and overhang on it (see image). This is a measurement from the nose of the tread to nose of the tread. You are not required to have an nosing/overhang on your stair treads.
How much difference between stairs?
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.
What is the IRC code for stairs?
The International Residential Code ( IRC) has specific instructions the way stairs can be built. Here’s a clear summary of what the IRC code says about stair rise, run and nosing. (Note: not every municipality adopts every part of every code, and some cities and states add in their own additional rules. Bottom line, check with your local building ...
How tall should a riser be?
Risers - the Step Height [F] is the typical height of each step. Code states that this should not be greater than 7 3/4 inches (194 mm). In a given run of stairs, the greatest step height and the smallest step height should not vary more than 3/8 inch (9.5 mm). Open risers with openings more then 30 inches (762 mm) vertical to the floor should not permit the passage of a 4-inch-diameter (102 mm) sphere.
What is the total rise of stairs?
Total Rise [A] - The total rise of a set of stairs is the vertical distance between the bottom of the first step and the top of the finished landing. The Total Rise should be not larger than 151 inches (3835 mm) between landings or floor levels.
How deep should a stair tread be?
Treads - the Tread Depth [B] should not be less than 10 inches (254 mm). In a given run of stairs, the greatest tread depth should not exceed the smallest by more than 3/8 inch (9.5 mm). Typically, a single 2x12 or two 2x6s are used for stair tread material.
How many stringers are there on a set of stairs?
In a set of stairs 36 inches wide, there are typically three stringers (one on each end and one in the middle). The stringer length is the tip-to-tip length of the cut stringer. It is used to determine the length of 2x12 material required to build the stair stringer. Total Rise [A] - The total rise of a set of stairs is ...
What is a stair calculator?
The stair calculator is used for calculating stair rise and run, stair angle, stringer length, step height, tread depth, and the number of steps required for a given run of stairs. For convenience and flexibility, this stair stringer calculator comes in two forms, the automatic and manual . Click on the [?] icons to determine the best calculator to use for your stairs.
How much headroom is needed for a stair tread?
Headroom - the headroom should not be less than 6' 8" (2032 mm), measured vertically from the stair tread nosing to the nearest ceiling object.
What is a stringer on stairs?
Stringer - The stringer is the structural part of a set of stairs. They are cut from 2x12s or larger material - the uncut portion of the stringer should not be less than 5 inches (127 mm) (see diagrams below). In a set of stairs 36 inches wide, there are typically three stringers (one on each end and one in the middle).
How wide should stairs be?
Stair width does not include handrails. Building codes generally suggest that stairs be at least 36 inches (91.44 cm) wide.
What is stair calculator?
The Stair Calculator is an online tool for calculating various parameters involved in the construction of stairs. Refer to the figure adjacent to the calculator as a reference. A fraction to decimal conversion table for common fractions used in measurements is also provided at the bottom of the page.
What is a nosing on a tread?
Nosing: The nosing is the protrusion at the edge of a tread that hangs over the riser below. Not all steps have a nosing, but when present, the nosing is included in the length of the tread. The main purpose of nosing is to improve safety by providing extra space on which a person can place their feet.
How high should a handrail be?
Similarly, handrails must be between 34 and 38 (96.52) inches high measured from the top of the treads, with a diameter between 1.25 inches (3.18 cm) and 2.675 inches (6.79 cm). Stringer: A stair stringer is a structural member that supports the treads and risers of a staircase.
What is headroom in stairs?
Headroom: Headroom is the height measured from the top of a tread to the ceiling above it. While building codes for headroom are primarily intended to ensure enough room for people to comfortably use the stairs, the codes typically require far more room than the average height of a person to allow for moving larger objects such as furniture.
How long should a tread be?
Building codes generally suggest that the minimum length of a tread be 10 inches (25.4 cm). Rise/Riser: The rise, or height of a step is measured from the top of one tread to the top of the next tread.
Where is the nosing measured?
Its length is measured from the outer edge of the step, which includes the nosing if it is present, to the vertical portion of the stair called the riser. Both nosing and riser are discussed below. When measuring total run of a staircase, the length of the tread above the last riser is not included in the measurement.