oak handrail

[jercol]

thread337-363257

Glass99, what did you wind up doing? I'm in the same situation and am not sure how oak handrails are justified....

 

[woodman88]

From the AWC website.

"Most rail systems are hardwoods and need a different set of design values (Note that most of the hardwoods used typically do not have a grade stamp, they would have to be graded in some way to determine design values, assuming they are in the NDS Supplement). Furthermore, no criteria for deflection exists for this application. The test criteria are commonly interpreted to mean ultimate load at failure."



Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[glass99]

jercol: formally, I kind of punted and went with the millworker's written assertion that their handrail was good with a 4ft span. For my in house purposes I went with a FOS of 3.0 on ultimate. The requirement for a glass balustrade is FOS=4.0 with a 1/3 allowable stress increase for handrail loads.

It is a bit of kludgy solution, but its the best I could come up with!

 

[jercol]

glass,

that kind of stinks. After quite a bit of spinning my wheels I talked to my client (a custom fabricator) and found they typically have steel insterts in the wood rail due to this issue.....

 

[Ron]

Oak handrails are typically routed to fit over a tube steel top rail. They are cosmetic, not structural.

 

[racookpe1978]

12 Jan 15 02:01
Oak handrails are typically routed to fit over a tube steel top rail. They are cosmetic, not structural.

Going to disagree with you here: The handrails (interior for example) I've installed are "furniture grade/trim grade" wood (no knots, no splits or flaws) and are supported every 4 inches by the ballusters from below (and by the wall or posts at both ends) on an outside rail; or by handrail supports from the studs every 16 or 24 inches down the inside wall.

Never seen any with an interior steel or iron support or plate at all.

The handrail is limited by grip requirements, but how are you (the original poster) using the wood rail's theoretical "strength" to calculate what? If a 200 lb force load is pushed "out" horizontally through the rail, the whole section of rail resists the force, and your strength is NOT due to the rail, but due to how you secure both ends of the rail into the wall, and how the ballasters and end points of the rail are supported. That is where the resistance is built up: NOT through drywall screws into drywall screwed holes!

 

[woodman88]

I got a handrail and supports from home depot, 1.5" round with a flat bottom for attachment to rail support, and I placed the supports at 4' o.c. Guess when I sell the house I should remove it?

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[glass99]

There are a lot of unreinforced 1.5-2" timber handrails out there. Home Depot sells them, and there are a bunch in high profile institutional projects around the place including the Lincoln Center in NYC. I have certainly run across reinforced timber handrails too. I would say its about 50/50 in my unscientific survey.

 

[jercol]

racook,

the ballusters are infill only. If you do that calculations on that they do not have the capacity to cantilever and resist the code mandated loads on the rail (200 lb point load at any point and any direction or 50plf which ever is greater) this is true even if you gang a whole bunch of them together.


woodman88,

there are a lot of things done in the residential world that are wrong. Most of the handrails in my house do not meet building code. The specific situation I had was a commercial structure and the eor and arch required calcs for the ornamental handrail package

 

[woodman88]

jercol

1) I disagree that "there are a lot of things done in the residential world that are wrong." As engineers using the IBC, we usually just calculate the individual members and not the overall system.

2) For your handrails what kind are they and if wood what design values did you use?

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.