Elevator Guide Rail Supports 1

[strucguy]

Good Morning

The contractor on one of the jobs I am involved in is proposing to use metal studs in the shaft wall to provide support for the elevator guide rails. Has anyone seen this approach before. On all my previous projects we ended up providing steel tubes that were designed for appropriate loads and deflection. I am a little skeptical about making studs do all the work. Can anyone throw some light on this? Thank you.

 

[dhengr]

Seems to me that you have to determine if the stl. studs, likely a built-up section, are strong enough and stiff enough for the concentrated lateral loads induced by the elevator. That’s the same thing you would have done to select the steel tubes which you typically spec. My guess is that std. stl. studs are a bit light and flexible, and will be left wanting in terms of connections.

 

[steellion]

Whenever the rails cannot span floor to floor and shaft wall is used, we end up providing vertical structural steel tubes. That's not to say that a built-up CFS section cannot be used, but I haven't seen it.

 

[NLefever]

Most elevator guiderail design are governed by deflection rather than capacity. I believe you typically want to limit it to 1/8" of deflection max, this should be verified for your code application. As such metal studs may be able to provide the support required from a strength perspective, but not necesarily from a stifness/deflection resistance perspective. I've always used HSS rectangular elevator guide rail supports, but thats also based on designing in the high seismic zones of California where seismic respeonse is significant.

 

[XR250]

As a metal stud designer, it really irritates me when the GC or EOR want to save some money by using light gage where tube steel should be.
By the time you design and detail the metal stud columns, they could have already installed the tube steel.
I run into this all the time. I am working on a job currently where the EOR forgot to design a piece of 30 ft. span tube steel to resist the wind load of a 19' tall wall and to carry the weight of the wall above the storefront. Rather than admit her mistake, she is forcing the light gage sub to construct a 30 ft. span header out of 14" material. Certainly, it can be done but it is so impractical that it is ridiculous.
It would make more sense for the light gage sub to simply pay for the tube steel but they don't see it that way. Just me fee to design it would likely cover half of the material costs.

 

[TDIengineer]

As a metal stud designer, it really irritates me when the GC or EOR want to save some money by using light gage where tube steel should be.
By the time you design and detail the metal stud columns, they could have already installed the tube steel.
I run into this all the time. I am working on a job currently where the EOR forgot to design a piece of 30 ft. span tube steel to resist the wind load of a 19' tall wall and to carry the weight of the wall above the storefront. Rather than admit her mistake, she is forcing the light gage sub to construct a 30 ft. span header out of 14" material. Certainly, it can be done but it is so impractical that it is ridiculous.
It would make more sense for the light gage sub to simply pay for the tube steel but they don't see it that way. Just me fee to design it would likely cover half of the material costs.

So true... it will be cheaper and faster in the long run to install the tubes... Just make sure you think about fire rating... Also, how are you going to use anything but shaftwall studs within an elevator for your 1hr or 2hr rating? A shaftwall CH stud is no heavier than 20 gauge.. good luck getting those to fly if you have any significant floor to floor height... plus how do you make the connection work to 20 gauge.. This is just a bad idea all around.

 

[strucguy]

ExcelEngineering...I feel your pain. But, this is a chicken and egg situation. Nobody knows what's needed until elevator sub comes on board. I remember asking the Architect if we need to include any Elevator guiderail support details. And, their answer was "no" as they didn't want to ask for something that may not be required. And, now it is between Arch and GC to figure out who's responsible for this. We did our part by offering to provide a steel tube option for free. But, the GC was hesitant as they figured the light gauge option would be more economical.