How to choose the glass thickness for a specific application
10.02.26
Glass thickness directly affects the safety, stability and durability of a structure. The right thickness depends on many factors: location, fixing type, loads and safety standards. In practice, the difference between 6 mm and 12 mm glass can decide whether a structure serves for years or becomes a source of problems. Below we discuss the key rules for choosing glass thickness for the most common applications.
What determines the choice of glass thickness?
The location is the first factor to consider. Exterior structures are exposed to wind, rain, temperature changes and mechanical damage, so it is no surprise that they need thicker glass than those installed indoors. For example, facade glazing is usually made of toughened laminated glass at least about 17 mm thick.
The fixing method also determines the required thickness. Glass held in linear systems, set in profiles along the entire edge, can be thinner. Point fixings, where the load is concentrated in a few places, require much thicker panels – often 12 mm or more.
The type of structure and its purpose directly affect the parameters. Glass balustrades with a protective function must withstand specified horizontal loads under building standards. Bathroom glazing, where there are no large mechanical loads, can be made of thinner glass.
Which glass thicknesses are used in bathrooms?
Bathrooms most often use toughened glass from 6 mm to 10 mm. 6 mm glass works well in standard framed shower enclosures. It is strong enough, light and easy to install.
For frameless shower enclosures, 8 mm or 10 mm is recommended. With no frame for support, the glass itself must provide stability. Thicker panels are stiffer and therefore safer in everyday use. In addition, sliding systems for shower enclosures often need thicker glass because of the extra dynamic loads when the doors slide.
Remember that shower enclosure hinges are designed for specific glass thicknesses. The manufacturer always states in the specification which panel thickness a hinge model is intended for. Fitting hinges that do not match the glass thickness can lead to damage and problems in use.
How does glass thickness affect the safety of balustrades?
Balustrades are structures where safety is the priority. The glass must withstand specified horizontal loads – typically about 1 kN per linear metre in residential buildings. This requires toughened laminated glass of the right thickness.
For interior balustrades in base channels, the minimum is usually 8.8.2 (two 8 mm panes bonded with PVB). Exterior or point-fixed balustrades need thicker make-ups – 10.10.2 or even 12.12.4.
It is worth understanding why laminated glass is used. Toughening makes glass strong, but when damaged it breaks into small pieces. The PVB interlayer holds them together, which increases safety, especially on upper floors and balconies.
Does thicker glass always mean better quality?
Thicker glass is not always the better choice. Every application has its optimum parameters. Glass that is too thick in a light structure increases cost, makes installation harder and may require stronger fixings. Glass that is too thin in a demanding structure risks damage and safety problems.
In installation practice, balance matters. For interior all-glass doors, 8 mm toughened glass is enough. Anything thicker would be unnecessarily heavy and need stronger hinges. Large-format shop fronts, on the other hand, use 10 mm glass or thicker because of their size and the risk of mechanical damage.
The type of processing matters too. Toughening increases strength up to five times compared with float glass. Lamination adds a layer of safety. As a result, thinner toughened laminated glass can be as safe as thicker float glass.
Which standards govern glass thickness in structures?
Polish regulations on glass in construction are general and often refer to “safety glass” without precise guidelines. That is why installers and designers often turn to the German DIN 18008 standards, which set out detailed requirements for different applications.
These standards define minimum glass thicknesses depending on the height of the structure, the fixing method and the loads. For example, a balustrade more than three metres above ground level requires thicker glass than one installed indoors on the ground floor.
For professional contractors, knowing the standards is essential. It helps avoid design errors and ensures compliance with building regulations. In public buildings the requirements are even stricter – additional certificates and approvals often apply.
What to look for when ordering glass
Above all, you need to know the exact dimensions of the structure and the type of fixings. The glass manufacturer needs this information to choose the right thickness and processing. Remember the holes for clamps, hinges and other fixings – they must be made before toughening.
The type of glass matters. Float, toughened, laminated and toughened laminated each have different properties and uses. Most structures, however, use toughened or toughened laminated glass.
Installation conditions also influence the choice. If the structure will be exposed to large temperature swings, moisture or strong sunlight, choose thicker glass with better parameters. An experienced supplier will help you choose the optimum solution taking all these factors into account.
Choosing the glass thickness is a decision that requires many variables to be considered. Safety, functionality and looks should go hand in hand. If in doubt, consult a specialist who will help you choose a solution tailored to your project.
