Handrail Post and Rail Minimum distance 3

[cgstrucg]

Hello All,

I am designing a concrete stair and handrail for it in the New York region. While concrete stair was easy, for some reason I am facing trouble while deciding the dimensions of the handrail. I would really appreciate if someone can please confirm the below-mentioned dimensions-

For the height of the handrail posts, I took 36" which complies with OSHA.
What should I do for end post to intermediate posts distance and top rail to intermediate rail distance? Are they necessary? I have 4ft high and 5ft wide stair which is pretty small and I don't think I need intermediate posts. But I can't find in OSHA as to what their minimum requirement is. I just saw the following -

"1926.1052(c)(4)(iv)

Other structural members, when used, shall be installed such that there are no openings in the stairrail system that are more than 19 inches (48 cm) wide."

Thanks

 

[JAE]

Well the IBC requires a 42” high guardrail along with a lateral load of 50 plf on the top rail or a concentrated load of 200 lbs at any point.

Post spacing depends on the resulting bending moment and capacity of the post.

IBC also requires a system that prohibits a 4” diameter sphere from getting through the guardrail assembly.

Not sure if your project falls under the IBC vs OSHA only.

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[JStephen]

1926 is the Construction regulations. General Industry stairs are in 1910.25 and 1910.29.
Note that choice of code (IBC or not) affects tread run dimensions among other things.

 

[IFRs]

For stairways, OSHA 1910 Subpart D section 29.b requires a top rail at 42", a hand rail at 36" and a mid rail at 21". Plus or minus for all. At 5 foot wide you should not need a rail down the center, OSHA has a 88" max before a center rail is needed. You do need to determine if you are fixed industrial stairs 1910 or construction stairs 1926 but "concrete" suggests fixed.

 

[cgstrucg]

What does it mean when they say that top rail should be 42" and top handrail should be 36". I don't get it. Is it like another rail on top of top handrail?

 

[RickyTickyTavi]

The top rail is a structural member for the system,

Top handrail is what the pedestrian puts their hand on. This link summarizes is better than I am:

https://www.deckmagazine.com/design-construction/railings/guardrails-vs-handrails_o

quick edit, this article makes references to the IRC, but the nomenclature should be mostly the same.

 

[IFRs]

Google is your best internet friend. See

https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9721

 

[JStephen]

Note that there have been certain recent changes in OSHA rules, with construction formerly mandated now prohibited, etc., so it's kind of a mess.

 

[cgstrucg]

Got it. Thank You all.

 

[Bagman2524]

A Guard (or Guardrail) is not the same thing as a handrail. The top of the guard/guardrails need to be 42" minimum. A handrail has to be between 34"-38".
A guard provides protection from falling to a lower level.
A handrail provides a holding component to assist in standing upright and not falling down to the surface being walked on.

All I know is P/A and Mc/I

 

[cgstrucg]

I have my clarity on guardrail, handrail and center rail, thanks a lot for this thread but can someone please clarify what should be done for Intermediary posts? OSHA specifies stuff as follows -

"1910.29(b)(2)(iii)

Intermediate vertical members (such as balusters) are installed no more than 19 inches (48 cm) apart;"

Does it mean we have to provide vertical posts every 19 inches? That looks extreme to me. I haven't seen stairs following the same in NYC.

 

[JStephen]

That spacing on intermediate members is if you don't have a midrail. With some stairs, you'll have a post at every tread, and in that case, you don't need the midrail. If you have the midrail, then you can space the posts out as allowed by loading and allowable stresses.

 

[cgstrucg]

That was really helpful. Thank You