glass wall design

[hikeandgolf]

I have a client (contractor) whose home owner wants glass walls on both sides of his stair openings, to create a glass tube sort of staircase. I turned down this portion of the job because I've never worked with structural glass before. I mentioned that I would help look for an engineer who could assist with this portion of the job. Does anybody know if this is something that a glass/window company would have an engineer they go to for jobs like this? Or is this something where we will need to find a structural engineer who specializes in glass before we go to the window company?

 

[MotorCity]

Fancy. So are the stair treads, landing, and handrail all supported by the glass?

 

[TehMightyEngineer]

I remember KootK was looking into glass engineering consulting way back when. Not sure if he pursued that but worth seeing if he's able to take this on; I know he's collaborated with other eng-tips members before and he seems to love these sorts of odd jobs.

If you can catch the eye of glass99 here on the forum he seems to be a good authority.

Otherwise, it definitely appears that glass structural engineers are few and far between.

Ian Riley, PE, SE
Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/

 

[JStephen]

There have been some older posts on glass handrails/guardrails, you might check if they had any information that would help.

 

[hikeandgolf]

Yes, the stair treads, landing, and handrails are all supported by the glass. I could design the tread and handrail connections if the glass were already designed, but I wouldn't know where to start in terms of designing the glass for the 5 psf out-of-plane load. I told the contractor that we don't have the experience in glass design to warrant us doing the engineering, and didn't want to risk under-designing any component. The family has three boys who could potentially go WWE on the wall, or a guest who's been overserved could tumble into the glass wall, resulting in an underdesigned wall collapsing on them. I don't need any sleepless nights thinking about something like this! Someone who gets paid the big bucks can take on this one. I saw an older post (2014?) that glass99 and someone else (maybe KootK) went into detail about this type of work, but not enough info provided for me to be comfortable designing these wall.

 

[masonrygeek]

Any chance to use glass block masonry? They have some amazing clear units nowadays -

http://en.sevesglassblock.com/.

 

[KootK]

- Some glass suppliers have internal engineers that would be capable of doing this kind of work but most do not. Often, the glass suppliers use external engineers even for the mundane window stuff.

- You probably need at least two people on board for consulting: a specialty engineer and a local glazing contractor. Much comes down to availability, shipping limitations, and preferred detailing given the skill sets of the folks likely to be doing the install.

- I'd keep clear of the thing unless it truly is your sense that the owner is willing to part with some serious money on this. Estimating this in an unknown market is a complete crap shoot but you could easily spend $20K on engineering and another $75K on the supply and install. And I don't see a Picasso or Beyonce in the BIM rendering. It can be a bit painful on these things when you go all in and end up with a client who's utterly disappointed in you because he or she had unrealistic expectation of what is achievable on a well to do homeowner's budget.

- When the thing is engineered, and you review the calcs, prepare to be disappointing yourself. While there is some expertise involved, in my opinion, it mostly just comes down to having the balls to be the guy that does it. A little FEM, a little fundamental hand calc'ing, and a lot of careful detailing... that's about it. If you want to be the guy who's got the balls to do it, I'd be happy to try and help you step through it.

What jurisdiction will the project be in?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[JLNJ]

I'm with KootK in that you need to get the Owner's expectations in alignment with what is possible.

If the Owner thinks the stair is going to by curvy and look like it's "floating", but you end up with a stair that is angular and reading like it's all glazing material, metal connectors, and handrail, then it won't be a success no matter how graceful the engineering.

 

[hikeandgolf]

KootK, the jurisdiction is Portland, Oregon.

 

[KootK]

I remember KootK was looking into glass engineering consulting way back when. Not sure if he pursued that but worth seeing if he's able to take this on; I know he's collaborated with other eng-tips members before and he seems to love these sorts of odd jobs.

Thanks for the plug TME. My collaborations with folks here have morphed into some of my funnest assignments. If it comes to pass, we'll discuss a reasonable kickback percentage.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[TehMightyEngineer]

If it comes to pass, we'll discuss a reasonable kickback percentage.

Much appreciated but not required. Just happy to help other engineers.

You can buy me a beer if we ever meet up, though.

Ian Riley, PE, SE
Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/

 

[KootK]

To my chagrin, I've found that effective business development relies less on quality work and more on reciprocal favor doing.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[TehMightyEngineer]

To my chagrin, I've found that effective business development relies less on quality work and more on reciprocal favor doing.

Sounds about right. Thankfully providing both does seem to generate the best results.

Ian Riley, PE, SE
Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/

 

[dik]

It's a matter of providing tempered glass with holes cut out for treads, leaving an ample gap at the top and a little at the sides to hold the treads in place with caulk. You do not want to put the glass in flexure from the treads. They look stiff enough that there will be little if any rotation, but, you want to prevent it. Tempered glass is quite strong, but, fails catastrophically. The glazing supplier should be able to provide the engineering services...if not, check with his glazing supplier.

Dik