Table of Contents
Below is a brief summary of the IRC Appendix Q requirements: The clear width for stairways above the handrail height shall not be less than 17 inches and not less than 20 inches in width below the handrail. Risers shall not be less than 7 inches and not more than 12 inches in height.
What is the minimum stair width?
The IRC stairs code states that, to comply with stairway requirements, the minimum width for residential stairs be no less than 36 inches. The stair riser code is up to 7.75 inches, and can not vary more than 3/8 of an inch. There are also section codes in place for standard stair tread dimensions.
How narrow can a residential staircase be?
(1) Stairways serving an occupant load of more than 50 shall be not less in width than 44 inches. Stairways serving an occupant load of 50 or less may be 36 inches wide. Private stairways serving an occupant load of less than 10 may be 30 inches wide.
How narrow can deck stairs be?
Minimum Deck Stair Width The maximum height of a single step is 7.75 inches, and all stair heights must be within 3/8 inch of each other, to keep the stairs regular. 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 comfortable stair width?
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. Comfortable two person stair widths range between 49” (125 cm) to 60” (152 cm). For three simultaneous users, a minimum of 74” (188 cm) is recommended.
What is the standard width of a residential staircase?
The average stair width in America is about 36″ wide which is actually the minimum according to most building codes. Though the entire 36″ isn’t used, it is enough to account for handrails which can take up a few inches.
Do stairs have to be enclosed?
There shall be no enclosed usable space under exterior exit stairways unless the space is completely enclosed in 1-hour fire-resistance-rated construction. The open space under exterior stairways shall not be used for any purpose.
What is the minimum opening for a staircase?
The generally accepted minimum width for a stairway is 36 inches. The width of the stair opening is 36 inches or the actual width of the stairway, whichever is greater.
Are winder stairs legal?
Winder stairs are permitted in the building code as of 2019. The code says the minimum tread width on the inside radius needs to be 6 inches. It also says that the tread depth at walk line of the stairs measured 12 inches in from the inside tread edge must be no less than 10 inches.
How wide can you make deck stairs?
The stair treads should be at least 36 inches wide. Despite these minimum requirements, we recommend that stairs should be at least 48 inches wide so they don’t feel cramped. The maximum allowable stair rise is 7 3/4 inches, and the minimum stair rise is 4 inches.
What is the legal step height in Australia?
In Australia, riser heights should be uniform across the flight and should fall between 150mm and 180mm. The nosing of each tread should generally not extend more than 30mm beyond the riser.
How is stairway width measured?
Therefore, the egress width of a stair is measured as the clear width above the handrails (between obstructions such as a wall, guard, etc.), unless handrails project more than 4 ½ inches into the stair, in which case the stair width is the measurement between the interior surface of the handrails plus 4 ½ inches on Jan 1, 2013.
How do you make narrow stairs wider?
Most interior steps are built from either hardwood, composite material or plywood and can be remodeled for more width. It’s not as difficult as you might think to add up to 1 inch to stair width and depth by adding a hardwood extension. Adding more than that could cause the stair tread to become unstable.
What is the 18 rule for a staircase?
Rule one says that rise plus run (r+R) should equal 18 inches. Why? That’s what most people find to be a comfortable stride on most stairs. You can cheat a bit up or down, but below 17” and more than 19” will result in steps that require strides either too big or too small for most people.
How do you calculate space for stairs?
Related Articles Measure the distance from the floor at the bottom of the stair location to the floor at the top of the stair location. Divide the total rise by the estimated unit rise height. Divide the total rise by the total number of risers. Multiply the number of risers by the width of your pre-selected treads.
How wide does a staircase have to be UK?
To stay within Building Regulations, a domestic staircase needs a rise of between 190mm and 220mm. When it comes to staircase width, there are no restrictions as such, but standard flights measure 860mm, and for a main staircase it is agreed that a width of between 800mm and 900mm works best.
What is a floating staircase?
What are Floating Stairs? Floating stairs are a type of straight staircase that is self-supported. Because of the self-supported design a floating staircase requires no extra support between the underside of the staircase and the floor below or a wall.
