Can a Glass Shower Screen Explode? What Actually Breaks Toughened Glass

If you've read a few forums, you've seen the stories. "Our shower screen randomly exploded yesterday, sounded like a car accident," wrote one CHOICE community member in 2022. It's a scary thought when you're about to put glass in your bathroom.

Here's what's actually going on, and what you can do about it.

First, why shower glass is toughened

Every frameless shower screen in Australia must be safety glass. The Building Code requires shower screens to comply with AS 1288 (Glass in buildings) and AS/NZS 2208 (safety glazing). For frameless screens that means Grade A toughened glass, at least 6mm thick. Ours is 10mm.

Toughening heats the glass and cools it fast, which locks stress into it. Glass maker Viridian says toughened glass is roughly five times as strong as ordinary glass. When it does break, it breaks into small blunt cubes rather than long sharp shards. That's the safety part.

The trade-off: because of that locked-in stress, toughened glass can't be cut, drilled or trimmed afterwards. Any holes are drilled before it's toughened. Ours arrives pre-drilled for the brackets.

What makes toughened glass break

1. Edge and surface damage (the most common cause). The NSW Government's toughened glass guidance says breakage "can occur when a small chip or weakening in the hard outer layer" disturbs the glass's surface tension. It also warns that breakage is more likely when an unframed edge is in close contact with another hard surface, and that poor installation increases the risk.

In practice, that means:

• Setting a panel down on its corner on tiles or concrete.
• Glass touching tile, a screw head or metal hardware directly, with no packer or gasket.
• A door that swings into a vanity, tap or wall.
• Overtightened brackets squeezing the glass.

A chip from install day might not break the glass that day. It can let go weeks later, which is why it feels "random".

2. Nickel sulphide inclusions (rare). Very occasionally, a tiny stone of nickel sulphide gets trapped in the glass when it's made. Over time it can expand and shatter the panel. Glass makers describe this as "extremely rare" and "extraordinarily rare". Heat soak testing (holding toughened glass at around 290°C for a couple of hours) reduces the risk but doesn't eliminate it entirely.

How to cut the risk

• Never stand glass on its corner. Rest it on its long edge on a folded blanket or timber blocks.
• Check the edges when it arrives. Look for chips before you install. If you find one, contact us before it goes in.
• Use the packers and gaskets. Glass should never touch tile or metal directly. Our installation drawings show 3mm packers under the glass for this reason.
• Don't overtighten. Snug is enough.
• Plan the door swing. Make sure a door can't hit anything hard when it opens fully.
• Squeegee, don't scrape. The NSW Government advises against abrasive and cream cleansers on shower glass. See how to clean a frameless screen.

If it does break

Toughened glass breaks into small cubes. Keep people and pets out of the bathroom, wear shoes and gloves, and sweep and vacuum carefully, including the shower drain.

If glass breaks because of a manufacturing fault, Australian Consumer Law gives you the right to a remedy. The ACCC says goods must be of acceptable quality, safe and free from defects.

Our glass

Every panel we sell is 10mm Grade A toughened safety glass made to Australian standards. Browse the range or size your screen in the configurator.