Handrail Spacing 1

[OSUWE2010]

Does anyone know how much space is allowed between two guardrails? I have seen anything from 4 inches all the way to 19 inches. Please let me know your thoughts and where I can find this information.

 

[manstrom]

If the intent is to prevent children and pets from falling to their doom. It is less than 4". It is in the IBC somewhere.

When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.

-R. Buckminster Fuller

 

[jguer005]

If you are using IBC 2009 or 2012, it would be in Section 1012. There are several items in there you may want to look at. Section 1012.4 says the "grasping surface" should be continuous. Section 1012.7 says the minimum clearance between a handrail and some "other surface" should be 1-1/2".

See which applies to your situation best. Typically, when I design handrails such as the one you have shown, I try to keep it continuous and just have the fabricator weld the sections together.

 

[RHTPE]

"Guardrail" is a rather generic term.

Context may influence the responses that you get. As a construction engineer when I hear "Guardrail" I think of something different from a handrail along a stair or a railing on a residential deck. Industrial applications may differ from residential.


Ralph
Structures Consulting
Northeast USA

 

[Signious]

It varies widely with the relevant code. Canadian code (Part-9.8.8.5) states:

-For code required guards in a non industrial occupancy:
"...will prevent the passage of a spherical object having a diameter of 100mm [4 inches]..."
-For code required guards in an industrial occupancy:
"...will prevent the passage of a spherical object having a diameter of 200mm [8 inches]..."
-For all guards which are NOT required by code:
-"... will PREVENT the passage of a spherical object having a diameter of 100mm ..." OR "... will PERMIT the passage of a spherical object having a diameter of 200mm..."
(basically preventing a child from hanging themselves, morbid but I think that is the intention here)

There is also a clause detailing that the guard must be constructed in a way that its parts can not be used for climbing over the guard

 

[TLHS]

The industrial occupancy guard clause in the Canadian code has always been confusing to me, since 90% of the guard rails I've seen in industrial facilities don't meet it.

I've searched for some sort of way to justify common practice in relation to that code.

I'm also generally confused about why the guardrail detailing requirements are in Part 9, since it presumably applies to buildings outside of the scope of part 9 but those requirements don't seem to be repeated elsewhere. It does mean that, technically, it doesn't apply to most types of industrial buildings, but it also means that it doesn't apply to large residential buildings which I assume wasn't the intention.

The strength requirements repeated in Part 4, but not the detailing.

 

[JStephen]

I'm not aware of anything that addresses the dimension you show in your sketch. The 4", the 19" are minimum spacings between horizontal rails of a handrail, and wouldn't apply to the dimension shown. I would try to keep it at a minimum, but am not aware of a specific limit on it, either.

 

[dicksewerrat]

It does look like a good place to trap children that run along sliding a hand on the top rail.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[wannabeSE]

I would not exceed 4" based on this OSHA Standard Interpretation:

https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=22312

 

[racookpe1978]

Recognize that usual 4 inch spacing is the largest open sphere that go through the rail. Thus, when I bend rods and bars into spirals and weld on leaves or bends, the final sum of all shapes welded on needs to prevent a 4 inch sphere from going through the final "mesh" of all objects. And, sometimes, that requires testing everything then bending a leaf or bowing out a spiral to a wider (or narrower) turn.

For simple verticals under the IBC/UBC, the 4 inch gap (hard conversion at 25.4 mm/inch!) is universal for stairs: But if you need a little more space, use a larger diameter rod (5/8 or 3/4 diameter), or you can get fancy and use a 5/8 x 5/8 square - but rotate the square bar so it is 5/8 x 1.414 = 0.88 inch each. Thus, each set of rod + space = 4.88 inches. Over a long span, that's much further than 4 inch on center.

 

[racookpe1978]

Section 1012.7 says the minimum clearance between a handrail and some "other surface" should be 1-1/2".

That particular 1.5 inch spacing is for the minimum distance between a handrail and a wall (typically) so your fingers and knuckles don't get caught between the handrail and the wall and tear up your hand. In this case, the 1.5 inch space at that particular location between the two separate handrail curves would probably NEVER ever be able to trap somebody's fingers, but it is easier to maintain the spacing at 1.5 inch than try to assume an inspector is going to think logically.

The "other" 1.5 inch requirement (or the equal "maximum grasp" lengths on formed wooden rails) are for a typical person to be able to grasp the handrail firmly before they fall: so a 1.5 nominal diameter (1-1/4 or 1-1/2 diameter pipe) handrail can be grabbed. a 4x4 can't be gripped at all, a 2 x 6 slab of wood cannot be grabbed as solidly as a smaller diameter pipe.

Note the almost conflicting assumptions going on: A wide bend handrail like that drawn cannot in any way "trap" a child's head, but equally, that style handrail cannot be assumed to prevent a child from getting past the rail and be prevented from falling down a hill or down into a hole or a floor lower down. But as a handrail, they can help adults get down a slope.

 

[tbuelna]

Based on the OSHA standard that wannabeSE linked, the basic criteria for gaps between adjacent sections of guardrail seems to be "close enough to prevent a person from falling through the space".