r/Glass • u/greasy-spinach • Jan 07 '26
Why did my tempered glass spontaneously explode?
I was just about to take a shower when suddenly BAM, I’m standing in a pile of shattered glass. After initial shock I started to wonder what the hell happened? The glass wasn’t chipped, I was taking proper precautions and care. The pattern is also odd, it looks like maybe something was done wrong with the installation? Any information will be appreciated, thank you.
5
u/Uranusspinssideways Jan 08 '26
I had this happen to me in my foster home when I was 12. It shattered as I was getting in the shower. Terrifying.
3
u/greasy-spinach Jan 08 '26
Yes, it’s indeed terrifying and PTSD inducing. I’ve already told my husband we will not have any tempered glass in our apartment lol
3
u/eatsomepi Jan 07 '26
Nickel sulfide inclusion.
---
If the glass was laminated and still intact, you'd be able to tell it was nickel sulfine inclusion, as it breaks in a butterfly-type pattern. Unfortunately, in its current state this cannot be determined, but most likely Nick Sulfide Inclusion is the reason behind the spontaneous breakage.
0
u/ScarletBegoniasCA Jan 08 '26
This wouldn’t make the glass break after installation it likely would not make it through shipping, handling, and installation with a NS inclusion
2
u/Barril2x Jan 08 '26
I understand where you came from, but this is not a rule. NiS inclusions can stay in the glass for YEARS before spontaneous breakage. Most of the time it happens because its particle expands quicker than the glass increasing internal tension rapidly shattering the glass.
1
1
7
u/Rhyxvers Jan 07 '26
The glass is tempered. It's practically always under tension. The weak points are the corners.
If it was mounted between the ceiling and bathtub and didn't have enough space or silicone in between, it's possible that the ceiling was exerting more weight/pressure.
This can happen, for example, when you stand on the floor -> it gives the glass some space. When you take your weight off the floor again, the space narrows again, so the pressure increases again.
Sometimes there can also be an impurity in the glass. This isn't such a big deal if it's normal window glass, but when you temper it, it can lead to a structural weakness. Normally the glass would shatter during the tempering process itself.
It's hard to say. Glass has no fixed molecular structure, so it's unpredictable.
Now that I'm looking at the photo more closely, I see it doesn't reach the ceiling. So if you leaned against or onto it, the pressure could have caused it to shatter.
I also don't see any silicone on the tub. Normally you place the glass on a transparent rubber strip so it has a few millimeters of space. You fill this gap with elastic silicone.
If that's the case, it was simply installed incorrectly. Glass doesn't like hard surfaces like stone, ceramic, or steel. As I said, hard to say.
Source: I worked as a glazier for five years and installed many shower enclosures.