Specification
PVB thickness guide: 0.38, 0.76, 1.14 or 1.52 mm?
PVB interlayer comes in multiples of a single 0.38 mm ply: 0.38, 0.76, 1.14 and 1.52 mm. Standard architectural glazing uses 0.76 mm. Balustrades, overhead glazing and walkable floors typically move to 1.52 mm. Automotive windscreens standardise on 0.76 mm. Security glazing uses multiple plies above that.
Why the ladder is in steps of 0.38 mm
PVB is manufactured at a nominal 0.38 mm ply — 15 thousandths of an inch, a legacy of the imperial origins of the flat glass industry. Every other standard thickness is a multiple of it: two plies give 0.76 mm, three give 1.14 mm, four give 1.52 mm.
This matters practically, because it means a processor can build an intermediate specification by stacking plies rather than sourcing a separate thickness. It also means that where a coloured or printed effect is needed at a particular total thickness, coloured and clear plies can be combined.
Thickness by application
| Thickness | Plies | Typical application | Notes |
|---|---|---|---|
| 0.38 mm | 1 | Decorative glass, interior partitions, picture framing | Minimum for a safety laminate in most standards; insufficient for structural work |
| 0.76 mm | 2 | Architectural facades, windows, automotive windscreens | The default specification for the large majority of laminated glass |
| 1.14 mm | 3 | Higher-load glazing, some balustrade specifications | Used where 0.76 is insufficient but 1.52 is over-specified |
| 1.52 mm | 4 | Balustrades, overhead glazing, walkable floors, stair treads | Standard where post-breakage load-carrying is required |
| 2.28 mm+ | 6+ | Security, blast and bullet-resistant glazing | Multi-ply build-ups, often combined with polycarbonate |
What thickness changes, and what it does not
Increasing interlayer thickness increases post-breakage strength — the capacity of the broken panel to keep carrying load and stay in its frame. This is why balustrades and overhead glazing step up: the governing case is not the intact panel but the broken one.
It also improves acoustic performance and impact resistance, and it accommodates greater glass surface irregularity, which matters when laminating toughened glass with roller wave.
What thickness does not meaningfully change is optical clarity in a quality interlayer, or the UV blocking, which is already above 99% at a single ply. Specifying thicker interlayer for UV reasons is wasted money.
How to select thickness
Work through these in order — the governing standard usually decides it before preference does.
Frequently asked questions
Can I use two 0.38 mm plies instead of one 0.76 mm sheet?
Yes, and this is common practice. The finished laminate performs equivalently, provided both plies are handled and stored correctly and the autoclave cycle accounts for the total interlayer thickness. Stacking plies is also how intermediate and mixed colour specifications are built.
What is the minimum PVB thickness for safety glass?
Most standards set 0.38 mm as the minimum for a laminate to be classified as safety glass, but the practical minimum for architectural work is 0.76 mm. Check the governing standard for the application class rather than working to the absolute minimum.
Does thicker interlayer improve sound insulation?
Somewhat, but far less than switching to an acoustic grade. Acoustic PVB uses a softer core layer specifically tuned to damp the coincidence dip, and outperforms a thicker standard interlayer at the frequencies that matter for traffic and aircraft noise.
Which thickness is used for car windscreens?
0.76 mm is the automotive standard, laminated between two thin glass plies. Acoustic and head-up display variants use specialised wedge or acoustic interlayers at the same nominal thickness.