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Stair Rise

dpohlman

Registered User
Joined
Jun 6, 2022
Messages
7
Location
Wisconsin
So my question is in regards to 1011.8 Vertical Rise of stairs

So I know this section says that maximum height between landings is 12', so with this I have 21 risers a 6 219/256" each. With my floor assembly and using 10 ft ceilings my actual height is 12' - 1 1/8", I still have 21 risers at 6 221/256" each.

Is this going to be flagged in code review for 1/128" in riser height. it will take the same effort to go up 12' as it would 12' 1 1/8"
 
Is this a joke? Are you really measuring the stairs to 1/256" accuracy?

And if the code says 12 ft max ... then 12'-1-1/8" is clearly 1-1/8" too much.
 
So my question is in regards to 1011.8 Vertical Rise of stairs

So I know this section says that maximum height between landings is 12', so with this I have 21 risers a 6 219/256" each. With my floor assembly and using 10 ft ceilings my actual height is 12' - 1 1/8", I still have 21 risers at 6 221/256" each.

Is this going to be flagged in code review for 1/128" in riser height. it will take the same effort to go up 12' as it would 12' 1 1/8"
They would be within their rights to flag this issue, and they have the code to back them up.

Whether they will or not depends entirely on the individual doing the plan review. Some would, and some wouldn't. Also consider that if you are in a commercial building, the requirements of the ADA might play a role at some point, and the ADA offers a lot less discretion on the part of the inspector.
 
Is this a joke? Are you really measuring the stairs to 1/256" accuracy?

And if the code says 12 ft max ... then 12'-1-1/8" is clearly 1-1/8" too much.
I am not measuring it at that specificity, Revit provides it as such, I was just using it to show that riser height is minimally changed, or the change would be imperceptible.

Right but what is the intent of the code, if 12 feet was chosen as how many steps before someone needs to rest, then I can prove that I have the same number of risers, I am just trying to make the decision if I need or want to pursue a variance for something so piddly or if I just reduce the depth of my trusses by 1"
 
Intent is great - if your plans examiner or inspector will make exceptions based on intent. Intent is not the code, and they are not obligated to accept intent. Some will, some won't, and some might do either one depending on how politely you ask, how their day is going, whether they have had trouble with you in the past, if they think it will set a precedent, if they are busy, if they are bored, if it's a pet peeve of theirs, if their boss will or won't back them up, if they have a large jurisdiction or a small one, etc.

It doesn't hurt to ask, but I advise that you don't give them trouble if they tell you no. It is much safer for a PE or inspector to default to the letter of the code than to make an exception.
 
Make your ceiling height 9'-10 7/8". NO ONE will know the difference. There are no efficiencies in construction for maintaining 10' lids.

As I have been told many times by plans reviewers, "You don't have a code problem, you have a design problem, which is not my problem"
 
Intent is great - if your plans examiner or inspector will make exceptions based on intent. Intent is not the code, and they are not obligated to accept intent. Some will, some won't, and some might do either one depending on how politely you ask, how their day is going, whether they have had trouble with you in the past, if they think it will set a precedent, if they are busy, if they are bored, if it's a pet peeve of theirs, if their boss will or won't back them up, if they have a large jurisdiction or a small one, etc.

It doesn't hurt to ask, but I advise that you don't give them trouble if they tell you no. It is much safer for a PE or inspector to default to the letter of the code than to make an exception.
Sad to say, all of that is true.

1.25"divided by 144" is .007813. Rounding up to 0.8% out of compliance and I would have to wonder who's gonna notice and why would they care.
 
I am not measuring it at that specificity, Revit provides it as such,
Like redeyefly says ... you have a design problem. Which is that you are letting the computer dictate how you work. You can set the display of the dimensions to a practical number, you just need to learn how to use the program. And ... you should set the tolerance to a value that conforms to generally accepted construction practices. If your project needs 1/8" accuracy, you should set the revit to show that. Anything more than that will get you laughed at ... like your 1/256" dimensions here. It shows you have no concept of real world activities.
 
Here is the issue, which logic has nothing to do with.

The 12ft maximum rise was set as how often someone needs to rest between ascending, not the number of riser heights you can get in for a certain number of treads.

The 12ft maximum rise is what the powers that be settled on for public buildings and the IRC & IBC Residential private exception for higher floor to floor between landings used the riser height as just one more to exceed the 144" to allow the extra distance.

However, the IBC and others use the 144 max and 144 / 7 = 20.5714 or 21 risers using maximum riser allowed as the divider.

Thus, in reality 144 / 21 = 6.857 for riser heights, not 7, but this is only based on dividing out the max risers.

When we expand on the logic of maximum rise between landings is not based on the number treads and risers, but over height change.

What I have always questioned is it's not based on travel distance as part of it.

Here is a question, what makes more sense,

I am not sure 35 treads at 14-inches with 4-inch risers traveling 490-nches or 40'-10" for 144-inches of rise is any better than

20 treads at 11-inches with a 6.911-inch risers traveling 220-inches or 16'-4" for 145.125" of rise,

But per code the first is compliant and the second is not and the first runs about 24'-6" further than the second.

The same goes for a ramp run with 30-inches max rise between landings.

Hence, at 1" in 12" your horizontal travel maxes out a 30ft, but at 1" in 19.875" you can go approximately 49.5 ft to get to the same height.

So does it take more energy to travel 36 risers at about 41ft to get up 12 feet or 21 risers at about 17ft to get up 12'-1.125" of rise.

However, the simple point is even if the plan reviewer lets it slide, that doesn't mean it will pass at final inspection and how many times has a new inspector come in at the end and the old one is out and the permit is stamped must meet compliance even if missed in plan review...

Thus, unless it is clearly approved by the building department as known and given in writing, the proper paperwork to go ahead, what seems like a obvious why not, can cost you major issues down the road.

Thus, simply 144 maximum rise between landings and change the floor plan to allow a drop landing at the top of the flight or a raised landing at the bottom of the flight.
 
I could see accepting 12’ - 1 1/8” as an error in the field, but not as a willful violation in design.
 
Intent is great - if your plans examiner or inspector will make exceptions based on intent. Intent is not the code, and they are not obligated to accept intent. Some will, some won't, and some might do either one depending on how politely you ask, how their day is going, whether they have had trouble with you in the past, if they think it will set a precedent, if they are busy, if they are bored, if it's a pet peeve of theirs, if their boss will or won't back them up, if they have a large jurisdiction or a small one, etc.

It doesn't hurt to ask, but I advise that you don't give them trouble if they tell you no. It is much safer for a PE or inspector to default to the letter of the code than to make an exception.
The real issue : Is that Plan Reviewer going to APPLY the Code OR INFLICT the Code.
The kind of Reviewer who would Inflict the Code with such a small difference Needs our Prayers
 
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The kind of Reviewer who would Inflict the Code with such a small difference Needs our Prayers
Disagree. as Jay Smith points out, it "could" be overlooked in the field as a construction tolerance, but it must be rejected on plans where it would be interpreted as a willful violation.
 
So does it take more energy to travel 36 risers at about 41ft to get up 12 feet or 21 risers at about 17ft to get up 12'-1.125" of rise.
If I remember my physics class from a hunnert years ago ... one HP is the energy needed to lift 750 lbs a distance of 1 ft vertically, and it didn't matter if you pushed it up a ramp or lifted it straight up.
 
If I remember my physics class from a hunnert years ago ... one HP is the energy needed to lift 750 lbs a distance of 1 ft vertically, and it didn't matter if you pushed it up a ramp or lifted it straight up.
Agree. Same amount of work. The rise and run of the stair is not relevant to the 12' between landings.
 
Disagree. as Jay Smith points out, it "could" be overlooked in the field as a construction tolerance, but it must be rejected on plans where it would be interpreted as a willful violation.
I appreciate your attention to detail BUT All construction has tolerances and just because the Designer chose to acknowledge the full Design Height on their drawing doesn't mean the Carpenter won't cut 1/4" shorter Or the lumber will SHRINK. The difference is not 6 inches. We call them 2x4's but do they measure a Full 2" x 4" NO it is nominal So I would consider it a Nominal 12 Ft Floor to Floor height and call it a day

I stand by my observation that there are those Who INFLICT the Code and those Who APPLY the Rules. We use Micrometers in Manufacturing Not Building Construction. A ball bearing has a different tolerance range.
Can we agree to Disagree and still respect the other's POV? I hope so. But in today's environment you can't be sure
 
It sure does not feel like the same amount of work when I climb a set of residential stairs with an 8" riser compared to a commercial set with a less than 7" rise. Maybe it is age and I have less horsepower than I did at 30.
Agreed. If you walked 10 miles across a flat surface, I don't think anyone would tell you that you didn't expend any energy.
 
I appreciate your attention to detail BUT All construction has tolerances and just because the Designer chose to acknowledge the full Design Height on their drawing doesn't mean the Carpenter won't cut 1/4" shorter Or the lumber will SHRINK. The difference is not 6 inches. We call them 2x4's but do they measure a Full 2" x 4" NO it is nominal So I would consider it a Nominal 12 Ft Floor to Floor height and call it a day

I stand by my observation that there are those Who INFLICT the Code and those Who APPLY the Rules. We use Micrometers in Manufacturing Not Building Construction. A ball bearing has a different tolerance range.
Can we agree to Disagree and still respect the other's POV? I hope so. But in today's environment you can't be sure
I would agree that there are certain areas where an official will need to use discretion for tolerances. If the code says something has to be a certain size, but does not provide a range, we certainly must use our discretion. But in this case, we do have a range binding the difference in elevation between landings of 0' to 12'.

I'm not trying to start a fight here, but you criticize those giving their interpretations that the stairs as designed do not meet code and thus would not accept them, then cry victim when other question on why you are not enforcing the code.

Respect goes both ways.
 
It sure does not feel like the same amount of work when I climb a set of residential stairs with an 8" riser compared to a commercial set with a less than 7" rise. Maybe it is age and I have less horsepower than I did at 30.
Agreed, that's why when I designed my own house, I built stairs with a 6 5/8" rise, with a 12" run. 17 risers, but I don't feel like I am climbing a mountain. I love them.
 
I could see accepting 12’ - 1 1/8” as an error in the field, but not as a willful violation in design.
Disagree. as Jay Smith points out, it "could" be overlooked in the field as a construction tolerance, but it must be rejected on plans where it would be interpreted as a willful violation.
I can see where a plan checker would have a problem whereas an inspector would not. The inspector has to consider the ramification tied to a correction to redo a staircase for 1.125". A plan checker sees a mistake on paper and the ramification is a change to the drawing. But here's the thing about that, unless you tell the plan checker and the inspector about the extra inch....they're never going to know.
 
Agreed, that's why when I designed my own house, I built stairs with a 6 5/8" rise, with a 12" run. 17 risers, but I don't feel like I am climbing a mountain. I love them.
Smart! Research tells me somewhere around 6 1/4 x 13 is where falls start to increase per use. My foot just doesn't fit on less than 12", thus forced to toe out and more likely to stumble and fall. 8x10 stairs coupled with the dysfunctional type 2 handrail, no wonder the US has a hundred billion dollars in stair injuries annually.
 
It sure does not feel like the same amount of work when I climb a set of residential stairs with an 8" riser compared to a commercial set with a less than 7" rise. Maybe it is age and I have less horsepower than I did at 30.
Not sure what your suggesting but sounds like taller rise/shorter run is more work for same flight with more steps with lower rise/longer run. I would agree.
 
as Jay Smith points out, it "could" be overlooked in the field as a construction tolerance, but it must be rejected on plans where it would be interpreted as a willful violation.
Agree.
In one sense 12' vs. 12' 1" is probably imperceptible and inconsequential in real life.
But the reasons we have prescriptive codes is to create a "bright line" regulation between (1) a yes-or-no immediately verifiable compliance with what society has declared "safe enough" vs. (2) a performance-based code compliance that requires so much research and documentation.

You are free to design taller risers if you can convince the AHJ via performance methods.
The other option is to reduce the vertical travel height.

I once had an existing home remodel (conversion of attic to occupiable space) where we were within 1/2" of eliminating one riser and tread, shortening the stair run length by enough to make it all fit as it joined the downstairs hallway. The owner electric to increase the hallway floor thickness by 1/2", installing 1/2" thresholds on every doorway that connected to the hallway, for a height transition. Problem solved.
 
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