KBIS speaker offers carpenters simple solutions for safer stairs.
By Doug Walter
The National Safety Council reveals that 12,000 people die in the U.S. each year from stair falls, second only to deaths in automobile crashes. We who design and build stairs have an obligation to our buyers to make them safer.
The industry tries to make stairs as compact as possible so as not to waste space. I’ve had carpenters proudly report that they’d saved one tread and riser, thinking that was a good thing.
“With a little extra thought and budget, you can turn an overlooked necessity into a valued amenity.”
Why not make the stairs a safer daily experience for buyers and a design element in homes and celebrate them? With a little extra thought and budget, you can turn an overlooked necessity into a valued amenity.
The IRC 2015 allows up to a 7 ¾” rise; what most builders do. But the commercial code the IBC 2015 limits rise to 7 inches (and run to 11 inches), based on research by OSHA and others. A 7” rise is comfortable and easy to navigate by users of all ages.
Short treads are an accident waiting to happen. While the IRC section R311.5.3 allows a run of 10”, nosing to nosing or riser to riser, a 10” run requires an 11” tread because of nosing overhang, the only safe way of descending is to turn your foot at an angle so more of it engages the tread.
The industry has fought code change for years that would mandate a rise and run of 7 and 11”, arguing that those stairs take up more space. But the average stair only accounts for about 40 s.f. of the typical 2687 s.f. American home.
If one added 2” to each tread, and perhaps one extra tread and riser, the additional room needed would only be 7 to 8 sq. ft. The average American home is 2687 s.f., that’s only an increase of ¼ of 1%. But the increased safety for years to come of the lower rise and longer treads is immeasurable.
Railings should be continuous, not stopping at newels or at landings.
Experts have described descending stairs as a controlled fall, and we are all a stumble away from disaster! People who are right handed might hold a railing going up, but not going down and vice versa since it isn’t their dominant hand. With two railings, there is added security for everyone.
The average person must be able to grasp a rail and curl his or her fingers around it to hold it tight. In the 80’s, there was a trend of using 2×6’s mounted upright, and calling that the handrail. Cheap, easy and modern. But your ability to hold that type of rail depends on grip strength, which declines with age. 1 ¼” to 1 ½”diameter rails are optimum.
Descending a stairway is one of the most dangerous things we do in the home, and poorly lit stairs are an accident waiting to happen. There are so many solutions: windows, skylights, lights, nightlights, illuminated handrails. It’s easier to get natural light to a stair that abuts an outside wall, but it’s not at all impossible for an inside stair with the use of skylights or solar tubes.
Code minimum for residential stairs is 36”, often 36” is the measurement of the shaft, not the walkable surface, which is reduced by stringers and handrails. I find 39” to 42” a better width; easier for people to pass going up and down, and easier for carrying things. Those extra inches allow the addition of a second handrail, both are within reach. People notice and welcome the extra room even though it’s an inexpensive luxury.
Per the IRC, all risers and all treads must be within 3/8” of each other. The reason: a carpenter who first swung a hammer in the 60’s told me that building stairs is a “sacred trust”. I had never heard that expression, but instantly knew what he was referring to. As designers and builders, we have a sacred trust with our homeowners, their family, their guests and all the future users of the stairway, that the stairs will be predictable.
Take just two steps down and your body memorizes the rise and run for the rest of the stair and adjusts stride accordingly. It’s disconcerting when stepping up or down more than others throws balance off. Going down is far more dangerous than ascending because when you fall going up, you are falling into or onto the stair, falling going down and you may tumble down the whole run of stairs.
Doug Walter, AIA, CMKBD is a Denver architect with 43 years experience; specializing in lighting, historic homes and accessibility. He’s presenting an accessible design class at KBIS 2022 called “Kitchens and Baths for All: A Fresh Look at Abilities.”