Guard deflection

[bill1952]

Is there a maximum deflection allowed for a guard in IRC? I searched but came up with nothing. I did learn OSHA allows 3" of deflection, allowing the top of a guardrail normally at 42" to deflect to 39". (Wow) Has anyone here measured guard rail deflection, perhaps to see if under the 200 pound load it's below 36" aff?

Same apply to infill under top of a guard? Any limit to how far the 50 pounds on 1 SF can deflect the infill?

 

[Yankee Chronicler]

The code establishes loads that guards and handrails must be able to sustain, but I don't believe the code establishes any limitations on deflection.

Unless there's something in ASCE 7.

 

[steveray]

I'd say L/240 in the IRC, but what do I know....

 

[TheCommish]

Is a railing a structural member?

 

[danSAA]

From Julius Blum railing catalog engineering section:

There are few, if any, regulations or code requirements limiting
deflection in a railing but ASTM has put forth the following
criteria regarding Maximum Allowable Deflection (∆max) in their
specification E985.
For horizontal load at midspan:
∆max = h⁄24 + L⁄96
For horizontal load at top of post:
∆max = h⁄12
For vertical load at midspan:
∆max = L⁄96
In many instances, the anchorage of the railing to the floor,
tread or fascia is subject to a degree of rotation which will add
an indeterminate amount to the deflection on the post and rail.
Anchorage and supporting structure must be as secure and rigid
as possible

 

[Yankee Chronicler]

I'd say L/240 in the IRC, but what do I know....

View attachment 15827

The immediate question then becomes, is a guard or a handrail a "structural member"?

From Julius Blum railing catalog engineering section:

ASTM E985 is not a referenced standard in the 2021 IBC. Therefore, it cannot be used by a code official to limit defection in a guard or a handrail. It is, however, useful as guidance for designers.