Vertical Stair Rise

[ToadJones]

I am designing and detailing some service stairs and walkways in an industrial facility.
I know OSHA and IBC say that the vertical rise in a flight of stairs should not be more than 12' without having a landing.
Does this still apply to stairs that might only be used twice a year?

 

[MiketheEngineer]

Yes - code is code

 

[ToadJones]

Mike-
What I am getting at is, is there any exceptions?
OSHA reads ".....that will not be a permanent part of the structure...." in reference to the stair height provision.

 

[JedClampett]

I've often wondered about this too. The sections on stairs in IBC are in regard to access and egress for fire events. If the building in not occupied, the stairs are for maintenance only, etc. I think there would be a strong case to ask for a variance.
Unfortunately, even the dumbest code reviewer knows the 12'-0" limit between landings, so you can never get away with more.

 

[dhengr]

Toad:
I don’t have either OSHA or the IBC in front of me, but you are not providing public ingress or egress to a building or a second f. of the bldg., where the general public needs a regular resting place in a full flight of stairs, or many people are involved in the vertical transit. Is there a rise limit on ships ladders? They sell 24' extension ladders were you live don’t they?

 

[CTW]

".....that will not be a permanent part of the structure...."
This passage comes from Part 1926, Safety and Health Regulations for Construction. You need Part 1910 for General Industry (which I think is now called Occupational Safety and Health Standards) since you're designing for an industrial facililty. Specifically 1910.24 for Fixed Industrial Stairs.

Section 1910 does not state a limit for distance between landings. dhengr is correct with regard to ingress and egress.

However, if there is a large vertical rise, and the space is available, I usually try to place a landing somewhere around 12 ft or mid-height. A long vertical rise when a person is carrying tools or equipment can become tiring in a hurry and it's nice to have a place to stop if needed.

 

[ToadJones]

Thanks for the insightful replies.
I have a rise of 23'-6" to negotiate.
The way it shakes out, 12' is great for the upper flight, which leaves 13'-6" for the lower.

 

[Bagman2524]

Agree with CIW. I don't see anything in 10CFR29 1910.24 (Fixed industrial stairs) that limits stair height to 12 ft. If you look at sections a & b of 1910.24 I'm not sure if you need a stair at all. If access to these areas are for infrequent maintenance you could probably use scaffolding as required to get to the area.

 

[msquared48]

11'-6" for the lower, Toad... 11'-6"...

God help us!

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[dhengr]

Boy! Now I’m really nervous having commented on industrial stairs, and encouraging their design. The way I see it, if Toad goes up 13'-6" to a landing, and then another 12' to the top, and steps off, he’ll fall 2' further than needs be.

 

[JLNJ]

OSHA lets you go 30' on a ladder without a landing. Ever climb a 30 ladder? It's tiring.

By the same logic, 23'-6" for a stair should easily be OK.

Your building official may see the stair and want it to be an egress stair, in which case it will need to meet the building code's requirement of 12'-0". Sometimes you can win the argument that it's just an equipment access stair, sometimes you can't talk him into it.

 

[ToadJones]

okay.
Everyone loves a smarta$$, including me.
The rise is 25'-6".
Mike & dhengr, give me some credit here.

90º turn at landing.
Mike & dhengr, please verify that I typed 90º and not 89º.
:-D

 

[CTSeng]

As CTW provided there is no limit for fixed industrial stairs for general industry in OSHA. However, some state OSHA regulations do include the 12' maximum rise. May depend on location.

But I also agree that it does depend on the inspector signing off on cert. of occup. Not trying to change direction of this thread but anyone else noticed the plan reviewers and inspectors are finding lots issues to gripe about recently? They're 'just trying to look busy' has hampered a few of my projects recently.

 

[ToadJones]

This is an existing structure. Not worried about occupancy.
Having said that, I have had numerous instances where inspectors knit-picked stuff that was completely outside the scope of their inspections. Drives me up the wall.

I had one inspector tell me on a residential project where we built a wrap around porch on a new house where the framing was of treated lumber. Not knowing where the posts that would support porch roof would look best, we designed and built the supporting deck with perimeter beams to handle the worst case porch post load at various locations (homeowner would not make up mind on where the posts would look the best).
In the end the porch posts did not line up with the posts supporting the deck. Since the porch was enclosed to the grade level it looked fine.
The inspector would not pass the framing because the posts did not line up. It was on the drawings that what we did was designed for. The idiot would not pass it and held the job up for more than a week. The idiot thought he was smarter than he was. I explained at length what was going on. The perimeter porch beams were essential transfer beams. I finally went to the county and raised hell.
A few days later there was another inspector on the site....the other guy had been terminated.
I hate to say it, but I think a lot of these guys are under-educated wanna-be's.

 

[woodman88]

You might look at the Alternating Tread Devices Exception in the 2009 IBC (Section 1009.7). It could get you 20' for the vertical rise in a Group I-3 for a 250sq/ft or less area to a control room or unoccupied roof. But this is new to the IBC.

Garth Dreger PE
AZ Phoenix area