How to Choose the Right Glass Thickness: 6mm, 8mm, 10mm or 12mm? 2026 Guide

4 July 2026Updated: 21 July 2026

Author: , Director, UAB Kevalita

How to Choose the Right Glass Thickness for Partitions, Railings & Showers

One of the most common questions we receive: what thickness of glass do I need? The answer depends on the application — partition, railing, shower, or door — and the specific load and span requirements. This guide explains what each thickness is suitable for and why getting it right matters.

Glass Thickness for Office Partitions

6mm glass: the minimum for aluminium-framed partition systems. The frame carries the structural load, so the glass only needs to resist wind pressure and accidental impact. Suitable for internal partitions up to 2.5m high in a framed system.

8mm glass: the standard for most internal partitions in framed systems. Better acoustic mass (sound reduction improves with glass weight). Common choice for office partitions up to 3m height.

10mm glass: required for frameless partition systems where no perimeter frame is present. The glass itself must carry all lateral loads. Also specified for partitions taller than 3m in some systems.

12mm glass: used for very tall frameless partitions (3.5m+) or high-traffic areas where extra impact resistance is required.

For guidance on which thickness fits your project, see our glass partitions page.

Glass Thickness for Railings and Balustrades

8mm tempered: not used on its own for railings — a broken tempered pane crumbles and leaves an open gap. In railings, tempered glass is used only as a layer of laminated glass.

8+8mm VSG laminated (two tempered layers): the minimum for railings — floor-mounted frameless balustrades, indoor and sheltered outdoor applications.

Exposed outdoor railings (high wind zones, coastal locations) or wider post spacings (1.2m+) need thicker laminated glass, e.g. 10+10mm VSG.

10+10mm VSG laminated: the standard specification for stair and balcony balustrades. VSG stays intact if broken — essential wherever there is a drop. Also used for overhead glazing (floors, canopies).

12+12mm VSG: for high-load or high-traffic stair applications, overhead glazing with larger spans, or where building regulations require enhanced safety glazing.

For glass railing specifications, see our glass railings page.

Glass Thickness for Shower Enclosures

6mm glass: not recommended for shower enclosures. Below the minimum for single-panel shower applications.

8mm glass: the standard for shower enclosures with framed or semi-framed construction. Adequate for most residential showers up to 2m height.

10mm glass: recommended for walk-in panels and frameless hinged door systems. Provides better rigidity, smoother door operation, and a premium feel. The weight (25kg/m²) helps doors close cleanly.

For shower glass options, see our shower enclosures page.

Quick Reference Table

6mm: framed partition systems (max 2.5m). 8mm: framed partitions, semi-framed showers. 10mm: frameless partitions, walk-in showers. 12mm: tall frameless partitions (3.5m+), high-traffic areas. 8+8mm VSG: railings and balustrades (minimum). 10+10mm VSG: standard stair balustrades, overhead glazing. 12+12mm VSG: high-load overhead glazing, commercial stairs.

If you are unsure which thickness is right for your project, we are happy to advise — free of charge — based on your specific application, span, and building conditions. We measure and install in Lithuania.

— Frequently asked questions

FAQs about this guide

What glass thickness do I need for a frameless glass partition?
Frameless glass partitions require a minimum of 10mm tempered glass. The glass must carry all lateral loads without a surrounding frame. For very tall partitions (over 3.5m), 12mm is recommended. In framed aluminium systems, 6–8mm is sufficient because the frame carries the structural load.
What thickness is required for glass stair balustrades?
For stair balustrades, we recommend 10+10mm VSG laminated glass as a minimum. This equals 21.52mm total thickness. VSG stays intact when broken, maintaining the barrier. 8+8mm VSG is the absolute minimum but 10+10mm is the professional standard for residential and commercial stairs.
Is 6mm glass strong enough for shower enclosures?
6mm is the minimum for framed shower systems but is not recommended for walk-in panels or frameless doors, where 8–10mm is required. Thicker glass provides better rigidity (especially for hinged doors) and a more premium feel. We recommend 10mm for any frameless shower application.
Does thicker glass always mean better sound insulation?
Thicker glass does improve sound reduction slightly — each step up in thickness adds roughly 1–2 dB. However, the biggest acoustic gains come from double-glazing (two panes with an air gap), not from using thicker single panes. For serious acoustic insulation (meeting rooms, offices), double-glazed systems (38–45 dB) far outperform any single-pane option.
How much does extra glass thickness add to the cost?
Moving from 8mm to 10mm glass typically adds 10–15% to the glass cost. Moving to 12mm adds another 15–20%. For safety-critical applications (stairs, overhead glazing), the extra cost is always worthwhile.

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