Why Tempered Glass Shatters on Its Own
Shower Screens, Tables & Doors (2026)

What spontaneous breakage looks like

Owners describe the same scene: a loud bang, often at night or when nobody is in the room, and a shower screen, a glass table top or a glass door turned into thousands of small cubes. Sometimes the panel stays in its frame for a few seconds, crazed all over, before it collapses. It is alarming, but the way it breaks is the safety feature working. Wikipedia notes that tempered glass is about four times stronger than annealed glass, and it is made so that it shatters into small pieces rather than long, sharp shards.

Spontaneous breakage is uncommon, but it is a known behaviour of tempered glass, not proof that the glass was fake. Understanding the causes helps you decide what to replace it with and how to stop it happening again.

The four common causes

Wikipedia explains that nickel sulphide inclusions most often come from stainless-steel machinery used in glassmaking, and that small shavings containing nickel change structure over time and grow until the stress exceeds the strength of the glass. This is why a panel can break years after it was fitted.

Reading the break: where did it start?

Before the pieces are swept up, look for the origin. A tempered panel usually has a point where the fracture started, with lines radiating out from it. Wikipedia describes the nickel sulphide break as a distinctive figure-eight pattern, with each loop approximately 30 mm in diameter. If the origin is at an edge or a corner, especially near a hinge, clamp or screw, edge damage or binding is the more likely cause. If it is in the middle of the panel, an inclusion is more likely. Knowing which it was tells the installer what to change when the new panel goes in.

What to do in the first hour

1. Keep children and pets out, and put on shoes. The pieces are blunt compared with ordinary glass but still cut.
2. If the panel is still in its frame, do not touch it or close the door on it; it can collapse without warning.
3. Tape a large sheet of plastic or cardboard over a crazed panel if it must stay up for a while.
4. Sweep and vacuum widely; small pieces travel far, especially on tiled bathroom floors and into the drain.
5. Look for the origin of the break before clearing it, and note where the hinges, clamps or fixings are.
6. Measure the opening and check the hinges and frame, which may need to be replaced too.

Where it happens most at home

Shower screens are the most common case: the glass is held by hinges and clamps at a few points, is knocked and slammed daily, and goes through hot and cold water every day. Frameless doors and screens put more stress on the fixing points than framed ones. Glass table tops break where they rest on metal legs or brackets without a soft pad. Sliding and folding glass doors break where a frame has settled and pinches the panel, or where a door has been slammed repeatedly against a hard stop. Our shower screen types guide compares framed and frameless screens, and our bi-fold glass door guide covers folding glass doors. Where privacy matters as well, our frosted film versus frosted glass guide explains the options for bathroom and window glass.

Reducing the risk

Nothing makes tempered glass immune to spontaneous breakage, but several things reduce the risk.

• Heat-soaked tempered glass: ClickBina's glass types guide describes heat soaking as testing the tempered glass at 290°C to trigger latent nickel sulphide failures before shipment, and as the mitigation for high-risk or overhead glass.
• Laminated or laminated tempered glass for overhead and high-risk places: if it cracks, the interlayer holds the pieces together.
• Careful handling and installation: no chipped edges, fixings set at the right angle, and soft setting blocks and gaskets so glass never touches metal.
• Correct hardware for the weight: hinges and clamps sized for the panel, adjusted so the door does not drop and rub.
• Door stops and soft-close hardware so doors are not slammed against hard surfaces.

A safety window film applied to a tempered pane can hold the pieces if it breaks, which Wikipedia mentions as a precaution where glass is overhead or in public areas.

Replacing the panel

Tempered glass cannot be cut, drilled or trimmed after tempering, so the replacement has to be measured and made to size, with every hole and notch in place before it is tempered. That usually means a measurement visit and a wait for the new panel. Ask for the same or better specification, the thickness to suit the opening, and whether heat-soaked or laminated glass is worth it for your location. Replace worn hinges, clamps and seals at the same time. For glass stair railings and balustrades, our glass railing guide explains where laminated glass is used.

What replacement costs

These indicative Klang Valley figures (2026) come from ClickBina's shower screen guide. Table tops, doors and railings are priced by size and glass type.

Heat-soaked or laminated glass, new hardware and any frame repair add to these figures and are quoted for the specific opening.

How ClickBina can help

ClickBina is an experienced KL & Selangor contractor for home refurbishment and trade coordination. Glass replacement is priced case by case: WhatsApp us your job details for a quote, including what broke, where it is, and the size of the opening. We reply within the hour, the price we agree is a flat price with no hidden charges, and a site visit is RM150, waived if you go ahead.

Sources & methodology

• Wikipedia, Tempered glass — strength, spontaneous breakage causes, nickel sulphide inclusions and the figure-eight pattern.
• ClickBina glass types guide — heat-soaked tempered glass and the soak temperature.
• ClickBina shower screen types guide — replacement shower screen prices.

How we estimated prices: every RM figure on this page is quoted unchanged from the ClickBina guide named above; they are indicative Klang Valley ranges for 2026, not fixed rates. The cause of a particular break can only be judged by examining the pieces and the fixings.