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Max. Riser Height Issue

sparrish

Member
Joined
Jan 26, 2011
Messages
2
Using BCNYS 2010 which is based on IBC 2006. I have a project with a floor to floor height of 17'-0" I designed a stair with 30 risers at 6.8" each & a landing at 11'-4" AFF. Another licensed architect in my office is telling me that I should be looking at designing it with 29 risers at 7.03". His reasoning is that OSHA only recognizes 7" as a riser height (no more, no less, exactly 7") & that there is a construction tolerance section of the code that would permit me to exceed the maximum allowable riser height explicitly stated in code.

I have only been licensed for 12+ years so I want to make sure I am not missing something. Thanks.
 
Not a NY ---- however, construction guidelines for stairs only apply to stairs used in construction - permanent stairs tend to be regulated by the state's adopted building code. I did not see anything in the federal guidelines but I may have missed something in the state public sector guidelines which I did not have time to cruise thru.
 
Welcome to the Forum!.....Let us clarify.....Are these the permanent stairs? If so IBC has a 7" MAX rise....3/8" deviation is allowed between your tallest and shortest, but not over the 7"....Hope this helps and someone else will probably chime in with some more input shortly...
 
Ask him to cite the 'construction tolerance section of the Code', lacking that OSHA has no authority to waive, modify or vary the Code. Section 1009.3 of the 2010 BCNYS specifically states that stair riser heights shall be 7 inches maximum and 4 inches minimum. I have no idea what OSHA has to do with it, but the code is clear.
 
On numerous anything in the OSHA regulations that dictate riser heights. The only thing that I have ever seen close to that in the OSHA regulations is regarding ladders.
 
If they are put in place for other than a means of egress, could make a difference. Hence the question of where they go.
 
OSHA has no authority to dictate design of buildings, nor the permanent stairs in them (except maybe in one of their own buildings...). The only 'tolerance' the Code allows is a maximum difference in height between the highest and lowest riser heights in any one flight of stairs. Maximum permitted riser height in the Building Code of NYS is 7" (with limited exceptions that do not apply to this proposal).

Unless and until your office mate can show you text in the Code to the contrary, his claim regarding construction tolerances is a fallacy at best.
 
Thanks for the input.

These are permanent stairs used as part of the means of egress. It is actually an unenclosed monumental stair in an atrium. (And yes, I did look at all of the requirements for monumental stairs, unenclosed stairs, shaft enclosures, atriums, etc.) I did some research into the OSHA standards, specifically 1910.24 which states that it "does not apply to stairs used for fire exit purposes." It also states that the angle of stairway rise shall be between 30 & 50 degrees.

I just wanted to make sure I wasn't missing something.
 
When the code provides a construction tolerance, I don't think this should be used for design. The architect is not constructing the stairs.
 
sparrish said:
there is a construction tolerance section of the code that would permit me to exceed the maximum allowable riser height explicitly stated in code.
I'm not familiar with that. What's the section number?
 
7" is 7" max.. while monumental stairs are not "the exit" in many buildings, that's where the people came in.. and that's where they will go out.. and where the fire department will come in. The 7-11 stair came into the code, I believe based on the limitations of a firefighter in bunker gear. "construction tolerance" may be the difference between being found guilty in a civil case.. or being found not guilty.
 
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