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walkereng
walkereng, Consultant
Category: Structural Engineering
Satisfied Customers: 2370
Experience:  Over 30 years of Structural Engineering experience.
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I would like to have an engineer design a steel staircase

Customer Question

I would like to have an engineer design a steel stringer for a staircase that we’ll be installing in a new house we’re currently building. I’ve talked with a local steel shop that will fabricate it, but they need engineering to tell them what size of steel to use for the tube, the tread plates, dimensions, etc.
I’ve included pictures that show nearly exactly what I’m looking for. It’s a switchback staircase, and basically I’d just like a single tube that runs down the middle of each section, with plates that I can bolt 4-1/8” thick x 41” wide x 10” deep red oak treads to. The tubes will also provide the base for the landing. I believe this will make sense once you’ve looked at the pictures.
Please let me know if you have any questions. Thank you!
Here are the details of the staircase, according to the designer (also found on Stair Info.JPG):
Finished floor height of 1st floor is 0”
Finished floor height of landing is -50 1/8”
Finished floor height of basement is -115 3/4”
Rise angle 37.87 degrees
Riser height 7-5/16"
Tread depth – Stringer must allow for 10” minimum treads
The Landing is 3’4.5” deep (front to back)
Attachment Info:
Single_Stringer4.JPG – This picture shows a stringer that is very similar to what I want.
Landing.JPG – This picture shows how I would like the landing. I would like to use a single 1-3/8” thick piece of red oak as the finished flooring on top of it.
Stair Info.JPG – Snippet of the architectural design program’s detail of the stairs.
Basement 3D.JPG – 3D Drawing of the staircase from the basement. It obviously does not have the single steel stringer we’re wanting to design.
Basement Blueprint.JPG – Snippet of the basement blueprints showing the stairs.
Submitted: 9 months ago.
Category: Structural Engineering
Expert:  StructuralEng replied 9 months ago.

Hello

Customer: replied 9 months ago.
Hello
Expert:  StructuralEng replied 9 months ago.

The treads look like they are glulam beams laid on their side. Is that correct?

Expert:  StructuralEng replied 9 months ago.

Never mind. I see you have red oak tread.

Expert:  StructuralEng replied 9 months ago.

I can size the tube for you as this question. If you need dimensioned drawings with connection information, plate information, etc. I can provide that as an additional service.

Expert:  StructuralEng replied 9 months ago.

The torsional component makes this different than a typical stair.

Customer: replied 9 months ago.
How much for everything?
Expert:  StructuralEng replied 9 months ago.

I'm not allowed to discuss cost in the chat. I can submit the offer for you to consider. If you accept, I will get pdf drawings to you by Sunday evening. It will include the stringer, plate connection between stringer and plate, connection of plate to tread. Connection of stringer to structure at top (I will need information about this existing structure. Connection of stringer to structure at bottom (I will need information about this existing structure). Do you need the mid-height landing designed, too?

Customer: replied 9 months ago.
I would like the landing to be supported by the stringer tubes. The picture shows what I have in mind. I would like to use a single 1-3/8” thick piece of red oak as the finished flooring on top of it.
Expert:  StructuralEng replied 9 months ago.

In the picture, the landing is supporting the stringers, not the stringer supporting the landing.

Customer: replied 9 months ago.
Not in the image "Landing.JPG". Look at that one.
Expert:  StructuralEng replied 9 months ago.

I see. That is different than the 'stringer' image. I strongly recommend the plate type in the 'stringer' image, but we can do the landing the way the 'landing' image shows it.

Expert:  StructuralEng replied 9 months ago.

I will need information from you about the existing structure at every location that the stair attaches to existing structure. I will make sure the connection is adequate to transfer the forces into the structure, but I will have to stop there and not continue to track the load through structure that I'm unable to observe and inspect. Is that reasonable?

Customer: replied 9 months ago.
that is reasonable. Please send the quote to***@******.***.
Expert:  StructuralEng replied 9 months ago.

I submitted the offer here. You should get the email.

Expert:  StructuralEng replied 9 months ago.

Did the offer go through?

Expert:  StructuralEng replied 9 months ago.

Hello. Do you still need help with this?

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