Tempered vs laminated (VSG) glass: which is safer and where to use each

Why ordinary glass isn't enough

Ordinary (float) glass, when broken, shatters into long sharp shards that can cause serious injury. Building regulations (LST EN 12600, EN 14449) require that glass structures exposed to potential human impact (doors, partitions, railings, showers) be made from safety glass — tempered or laminated.

Tempered glass (ESG / Tempered)

The glass is heated to ~620 °C, then rapidly cooled with an air jet. The surface contracts and compresses the core — making the glass 4-5 times stronger than ordinary glass. When broken, it shatters into small (~3-5 mm) harmless cubes. Standard: EN 12150-1.

Advantages: stronger (impact and heat resistant), cheaper than laminated, lighter.

Disadvantages: when broken, the entire pane fails at once (falls out of the structure), it cannot be cut or drilled after tempering, and there is a small risk of spontaneous breakage from nickel sulphide inclusions (~1 in 10,000).

Where to use: shower enclosures, interior doors, partitions, furniture, glass railings (combined with lamination) — wherever impact resistance matters but a fall from height isn't a risk.

Laminated (VSG / Laminated)

Two (or more) glass layers bonded under heat and pressure with a PVB interlayer (Polyvinyl Butyral) or SGP film (DuPont SentryGlas, an even stronger option). When broken, the glass remains stuck to the film — it doesn't fall down or scatter. Standard: EN 14449.

Advantages: safe even after breaking (residual strength), UV protection (PVB blocks >99% of UV), better acoustics (with an acoustic interlayer), can be cut to size before lamination.

Disadvantages: more expensive (~30-60%), heavier (two glass panes), edges must be properly finished (moisture can damage the film). Less heat-resistant than tempered.

Where to use: glass canopies, balcony / staircase railings, storefronts, shop windows, automotive windscreens — wherever there's a risk of falling from height or where anti-burglary protection is needed.

Combined option: VSG made from two tempered panes

The premium solution for railings and canopies is VSG made from two tempered panes (e.g. 2× 6 mm tempered + PVB). Even if one layer breaks, the other holds the structure. This is the standard for balconies in Lithuania when the panel has no top rail. Price: ~50% more than plain tempered.

Quick selection table

• Interior doors, shower enclosures → tempered
• Office partitions (without acoustic requirements) → tempered
• Partitions with acoustics 38+ dB → laminated with acoustic interlayer
• Railings for stairs, balconies → laminated (VSG made from tempered)
• Canopies, overhead structures → laminated (VSG made from tempered)
• Storefronts, anti-burglary protection → laminated (thicker interlayer)

FAQ

Can you tell them apart by sight?

Tempered glass looks like ordinary glass from the side (a small 'ESG' or CE mark is etched in the corner). The edge of laminated glass is visible — you can see a thin (0.38-1.52 mm) PVB layer between the two glass sheets.

Can tempered glass be cut?

No. The stress created during tempering means that any cutting, drilling or edge grinding after tempering will cause complete shattering. All measurements and openings must be formed before tempering. A mistake means replacing the entire pane.

How does laminated glass age?

High-quality VSG (PVB with properly finished edges) lasts 25+ years. Cheap quality or damaged edges can cause delamination — visible white streaks at the edges after 5-8 years. SGP film (DuPont) is moisture-resistant and used for outdoor structures.