Glass types sound technical, but the difference between laminated and tempered glass is easy to understand, and it explains a lot about impact windows.
Tempered glass
Tempered glass is heat-treated to be much stronger than ordinary glass. When it does break, it crumbles into small blunt pieces instead of dangerous shards. That is why it is used in shower doors, glass tabletops and car side windows. But once it breaks, the whole pane falls apart and the opening is open.
Laminated glass
Laminated glass has two (or more) layers of glass bonded to a clear interlayer. If it breaks, the pieces stick to the interlayer and stay in the frame. This is how windshields work, and it is the key feature of impact windows.
Side-by-side
- Tempered: strong and safer when broken, but falls out when it fails.
- Laminated: may crack, but stays in place, so it keeps the opening sealed and is harder to get through.
Where each is used in glazing
Frameless glass walls, shower doors and interior partitions often use tempered glass. Hurricane windows and doors use laminated glass. Some products combine both. See our frameless glass partitions guide for interior glass, and how impact windows work for the hurricane side.
How each type is made
Tempered glass is heated to a high temperature and cooled rapidly. This puts the outer surface in compression, which makes it several times stronger than annealed glass of the same thickness. Laminated glass is made by bonding two layers of glass with an interlayer under heat and pressure until it becomes a single sheet.
Where the building code requires safety glass
Codes require safety glazing in hazardous locations such as doors, panels next to doors, windows near floors and in shower and tub areas. Either tempered or laminated glass can satisfy those rules. That is why a glass shower door and a hurricane window use different glass for different reasons.
Other benefits of laminated glass
- Sound: the interlayer dampens noise. See noise reduction.
- UV: blocks most UV light, protecting furniture and floors.
- Security: holds together when struck.
Can a window use both?
Yes. Some impact assemblies pair laminated glass with other strengthened layers or with an insulated air space. The tested approval for the full unit is what counts.
Common questions we hear
People often ask whether tempered glass is "enough" for hurricanes. Tempered glass alone is not designed to stay in the frame after it breaks, so it does not provide opening protection by itself. For interior partitions and shower doors, tempered glass is ideal. See interior glass doors.
Frequently Asked Questions
Is impact glass tempered?
Impact glass is laminated. Some assemblies combine laminated glass with tempered or heat-strengthened layers, but the key is the interlayer.
Is tempered glass safer than regular glass?
It breaks into small pieces that are less likely to cause deep cuts, which is why it is used in doors and showers. It does not hold together like laminated glass.
Can you cut laminated glass after it is made?
It is made to size. Orders are manufactured to your measurements.
Is laminated glass the same as a car windshield?
The principle is similar. Windshields use laminated glass so that broken pieces stay stuck to the interlayer.
Ready to talk about your project? Get a free written quote (usually within 48 hours) or call 786-343-4729. EZ Glazing Corp is licensed and insured (License #SCC131153391) and handles the permit and inspection.