Frameless glass shower doors have made their mark in the trendy and innovative world of bathroom remodelling and accessories. Their unique designs embrace three major aspects: fluidity, flow and openness. Even when you take their safety concerns into account, there are plenty of reasons why frameless glass shower doors make for a good investment. The glass does after all go through a tempering process and rarely breaks. If it does, the pieces are very small.

But spontaneous glass breakage does occur. Let’s look at this uncommon phenomenon.

Spontaneous Glass Breakage: A Rare Phenomenon

After the updated safety glass benchmark set by the Canadian General Standards Board (CGSB), the use of laminated and tempered glass has been specified. Even the National Building Code of Canada (NBCC) and the International Building Code (IBC) has specified this.

No matter how uncommon it is, spontaneous breakage of tempered glass shouldn’t be overlooked. After all, a suddenly exploding glass shower door is kind of unreal. How can glass break by itself?

What Exactly Happens?

Suddenly exploding glass shower doors share certain common characteristics.

• Explosive Shattering Instead of Cracking

In the case of spontaneous glass breakage, there are no cracks in the glass to notice or fallen pieces on the shower floor. This is problematic since there are no warning signs and an apparently intact shower door may simply break into pieces suddenly. Homeowners who have experienced this have described the sound as deafening.

• Spontaneous Explosion

A sudden, loud explosion doesn’t mean that the shower panel will fall out of its frame, crashing to the floor. You may not even see any door brackets coming loose. Instead, the glass panels shatter from the centre outward.

• Midnight Explosion

This is another pattern of sudden glass breakage that occurs in the middle of the night. It begins with a crack and ends in an explosion. There have been instances where the middle of the glass door simply blew apart, leaving the glass shards within the frame.

The Cause

There’s been much speculation about this strange phenomenon. But some theories may come close to explaining why some glass shower doors explode suddenly.

1. Thermal Stress

As the temperature changes from warmer to cooler in your bathroom, it may affect tempered glass. Like other materials, glass expands and contracts with respect to temperature changes. That’s why most modern glass doors have resilient blocks at the bottom which provide room for expansion. In the absence of adequate space, the glass may end up bound to the frame. As a result, internal stress will develop which, once the strength of the glass has been exceeded, will cause an explosion.

2. Poor Installation

Larger doors made with sealed insulating glass that have absorbed heavy amounts of heat or have a reflective coating have the highest chance of exploding. Due to the coating being applied to the inside face of the outer part of the pane, the outer part tends to heat up more than the inside. This obstructs the natural expansion and contraction of the glass, causing it to break. This can be avoided by making sure your glass shower door has been installed with 100% precision.

3. A Nicked Edge

A subtle cut or damage to the edge of the glass caused by a screw or bolt can cause the entire panel to fall apart. This is the result of poor installation. Any incorrect positioning of the glass door will increase the chances of it being damaged by the hardware and fasteners used to keep it attached to the frame.

4. Manufacturing Defect

While making float glass, sodium sulfate is added to remove bubbles during the melting procedure. Glass doors may be contaminated by the presence of nickel, which can form nickel sulphide inclusions with sulphur. This can occur at any stage of the glassmaking process, or the nickel contaminants may be present in the raw materials from the beginning.

The most common reason for this incident is the use of stainless-steel equipment for making and handling glass. Even a small amount of nickel can alter the structure of tempered glass over time and create stress.

Special Mention

Actual injuries occurring from an exploding shower door glass are rare. Tempered glass tends to break into very small pieces, as mentioned. However, its greatest strength is also its greatest weakness. The tempering process impacts the tensile strength of the material and makes it more susceptible to direct impact, especially around the edges.

Glass shower doors may also break when the top roller loosens. Missing rubber bumpers on sliding tracks can also cause the door to hit the side track and break.

Sudden shower door breakage is rare but does happen. Correct installation by an expert and inspection of your beautiful glass door at regular intervals is the best way to ensure it remains in one piece.