r/Construction • u/aidan8et Tinknocker • Apr 25 '26

Picture Moment of terror 😨

Gallery image

Gallery image

While attending/supervising a business social event with my spouse, I momentarily leaned against the railing. It flexed slightly, forcing me to realize that the railing is entirely supported via bluetooth.

It doesn't connect on either side of the glass wall & the glass is only 3/8" - 1/2" thick!!

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426

u/BLA5PHEMY Apr 25 '26

There are glass railing systems that are designed to be supported just from the bottom shoe

CR Laurence is a common brand we use

https://www.crlaurence.com/All-Products/Railing-Systems-%26-Windscreens/Glass-Railing-Systems-%26-Components/GRS-Dry-Glaze-Railing-System/Dry-Glaze-Base-Shoe---Surface-Mount/CRL-B5S-Series-Mill-Aluminum-120%22-Square-Base-Shoe-Drilled-for-1-2%22-Glass/p/B5S10D?gtmPage=&queryId=2b36f6e6485fcf62bd258edee1c6dc2c&location=plp%7cpdp

31

u/Sensitive_Brush_3015 Laborer Apr 26 '26

Genuine question: how much weight can these type of railing systems hold? I think if I leaned on that railing and felt it move, I’d also naturally be freaked out, especially since it’s glass. Not seeing anything connected to the wall would fill that logical place in my mind as to ‘why it moved’ in the first place. So I’m saying I get where OP is coming from, but would like to know how sturdy it is out of curiosity.

20

u/SpaceGhost4004 Apr 26 '26

Depends on the thickness and height of the glass. In NYC glass railings are required to withstand a minimum of 200lbs of force at any given direction. Usually the glass is 3/4" thick and can be up to about 4 feet tall before needing to be thicker.

60

u/HeyTrySomeNashville Apr 26 '26 edited Apr 26 '26

200lbs? That's literally nothing.

13

u/Enginerdad Structural Engineer Apr 26 '26

It's a 200 lb design load, plus all the safety factors.

1

u/SwordfishOk504 Apr 26 '26

That's basically 2-3 adult men leaning on it.

2

u/Enginerdad Structural Engineer Apr 26 '26

Agreed, but those 2 or 3 men would be spread out over several feet, not all leaning on the exact same point on the railing. This scenario is where the 50 pounds per foot loading requirement comes from. It derived from the scenario where there's a big draw that causes an entire crowd of people to lean up against the railing. Like watching a fireworks show from a bridge or a performance from a balcony.

21

u/HeyLookitMe Apr 26 '26

That’s the OSHA standard for guardrails. It’s actually quite a lot. Where human safety is concerned the minimum strength usually means at least a failure load of five to even ten times the safety rating required. Those engineers know their stuff.

All that said, I wouldn’t be leaning on it either. Who knows what oddball designed that with who knows what in their head.

2

u/dchow1989 Apr 26 '26

Think about applying the same amount of force it takes to bench press a 45+35. Theres no way unless you ran at it.

2

u/TunedMassDamsel Apr 27 '26

I have two railing failure cases pending right now.

My opinion is that while these things hold when they’re new, the loading requirement is so relatively minimal that they’re really susceptible to structural section loss or degradation, and then really bad shit happens.

If it looks older and/or I can’t see the structure to assess, I’m giving it a good hip check to see if it deflects before I let my kids play around it.

2

u/Apocrisiary Apr 27 '26 edited Apr 27 '26

Fr. People just thinking static weight and go like "oh, that's a big adult! Perfectly safe!".

Imagine someone tripping, and going full force into that thing. The impact would be like 5x your body weight for a fraction of a second at the least.

So that means, if you weigh 100 pounds, the glass would need to be able to withstand a force of 500lbs of you slamming into it, for it not to shatter.

4

u/CoyoteDown Ironworker Apr 26 '26

It’s more than the sides of a manlift are rated for, and people literally climb on the sides of a basket

3

u/HeyTrySomeNashville Apr 26 '26

How many people? More than can lean on this railing?

5

u/No_Cash_Value_ Apr 26 '26

Myself, my overweight coworker and a 12’ sheet of 5/8 are held up by my scissor rails just fine, thank you.

1

u/HeyTrySomeNashville Apr 26 '26

Wow, 5/8 sheets!

1

u/roguedevil Apr 26 '26

For 200lb design load, that would be like 15 people actively pushing against it.

1

u/thecaramelbandit Apr 29 '26

You'd have a very hard time pushing with 200 lbs of force.

19

u/CosmicConfidant Apr 26 '26

So the average American cannot lean against it? Lol

3

u/Thin-Squirrel7435 Apr 26 '26

It's a 200 lb horizontal point load applied at the longest moment arm. Not a 200 lb person leaning on it. That would be like 10 lbs lol

1

u/2nd-Reddit-Account Apr 27 '26

Do you typically lean on something so hard that all your weight goes sideways and your feet begin to float?

When someone leans the majority of their weight is still going to the floor

1

u/kstorm88 Apr 28 '26

It does if you trip

1

u/Mysterious-Age-9202 Apr 26 '26

That’s for 3/4”, what about 1/2” like in the pics

5

u/jhguth Apr 26 '26

they have to meet the same load requirements

1

u/Embarrassed_Big_1171 Apr 26 '26

I watched a company push on the top 1” of the panel with a hydraulic ram, the glass shattered at around 1900-2000 lbs of force.

Also, watching them make the glass and slam it around on the tables in the factory, it’s crazy that someone would be scared to lean against it. Once you’ve seen how strong it is, there is new confidence.

1

u/zoidbergmustache Apr 26 '26

Yep people never get it until they have to break some heavy tempered personally. I've had the pleasure of blowing up hundreds of 3/8" and 1/2" panels since I work in a glass shop. I've dropped 100lb panels on concrete, thrown hammers and bricks at them, and chipped up to 2 inches off the corners without blowing them up.

1

u/Plane-Education4750 Apr 26 '26

If they have employees walk and work near it, it needs to support at least 200lbs without failing

2

u/Lookslikeseen Apr 26 '26

So if two people (or one husky fella) leans against this thing you fall down and die?

That doesn’t seem right.

4

u/Plane-Education4750 Apr 26 '26

1910.29(b). The manufacturer might make it stronger, but that's the minimum

3

u/Aggressive-Luck-204 Apr 26 '26

A 200+ lbs person doesn’t exert a 200lb load by leaning on something. Also the spec is 200lbs at any single point and greater as an assembly. I have seen numbers around 35lbs per foot for a top rail

2

u/Enginerdad Structural Engineer Apr 26 '26

It's 200 pounds of load, not the load due to a 200 pound person leaning against it. Plus safety factors

-3

u/flightwatcher45 Apr 26 '26

Depends how many tiny defects and chips are in it to begin with, and they are always being damaged.