Tempered vs. Laminated Glass: Understanding the Differences

Both tempered and laminated glass qualify as safety glazing, but they work differently and suit different applications. According to CPSC standards, understanding the distinction helps you choose correctly.

Tempered Glass

According to ASTM International, tempered glass is:

How it's made: Glass is heated to ~1,200°F, then rapidly cooled. This creates surface compression and core tension.

How it breaks: Shatters into small, relatively harmless granules (like automotive side windows)

Strength: 4-5x stronger than annealed glass of same thickness

Limitations:

• Cannot be cut or modified after tempering
• Can fail spontaneously (rare) from nickel sulfide inclusions
• Once broken, opening is fully exposed

Best for:

• Shower doors and enclosures
• Sliding glass doors
• Windows in hazardous locations
• Table tops

Laminated Glass

According to FGIA, laminated glass is:

How it's made: Two or more glass layers bonded with plastic interlayer (usually PVB or SGP)

How it breaks: Glass cracks but stays bonded to interlayer—doesn't fall apart

Strength: Similar to annealed glass, but holds together when broken

Limitations:

• More expensive than tempered
• Heavier than single-pane tempered
• Edges can delaminate if exposed to moisture

Best for:

• Skylights (glass stays in frame if broken)
• Hurricane-prone areas
• Security applications
• Sound reduction
• UV protection

Side-by-Side Comparison

According to CPSC and FGIA:

| Property | Tempered | Laminated |
|----------|----------|-----------|
| Impact strength | 4-5x annealed | Similar to annealed |
| When broken | Falls apart (safely) | Stays intact |
| Cut after manufacture | No | No (without specialized tools) |
| Post-break security | None | Maintains barrier |
| Sound reduction | Minimal | Good |
| UV blocking | Minimal | 99%+ |
| Cost | $ | $$ |

Code Acceptance

According to CPSC regulations (16 CFR 1201), both are acceptable safety glazing for most residential applications. Building codes may specify one type for certain locations (skylights often require laminated).

The Bottom Line

Tempered is stronger and cheaper—ideal for most residential hazardous locations. Laminated maintains the barrier after breaking—better for skylights, security, and hurricane zones.

*For complete safety glass guidance, see: [Safety Glass Requirements](/guides/safety-glass-requirements)*