VEKA: Large-format windows only with class A profile

The demands on the quality of large-format windows are higher than in the case of regular glazing. Primarily, it concerns the load-bearing capacity of the window and its static properties. For instance, a window measuring 4 m² can weigh up to 160 kilograms, and such weight cannot be sustained by every frame over a long period. Therefore, consulting with an expert on the choice of window frame is advisable.

The prerequisite for a long lifespan of the window is a quality profile

The large-format window frame must safely bear heavy insulating glass without deforming and withstand frequent handling. The thickness of the walls of the main profiles has a crucial influence on the rigidity of the window, its durability, and the glazing options. Given the energy standards, for which insulating triple glazing has become the norm, the most reliable solution for the long lifespan of windows is profiles of class A, whose main walls have a minimum thickness of 2.8 millimeters – in the case of class B, it is 2.5 millimeters. "The difference of 0.3 millimeters in the wall thickness of the main profiles of class A and class B may seem insignificant, but it has a considerable impact on the long-term load-bearing capacity, stability, and strength of the window," says Milan Klepsa, a representative of VEKA, a leading global manufacturer of plastic window and door profiles of class A, and adds: "The trend of large and heavy glazed areas logically brings a significant increase in the load on frame constructions. By using class A profiles for the opening parts of windows, you essentially eliminate problems such as wing deformation, profile deflection, leakage, or hardware pull-out, which are at risk with less stable profiles."

Demanding tests in the certification and testing center as a guarantee of quality

When selecting windows, we should certainly not underestimate their weight. For large-format ones, it is also necessary to use thicker glass (six millimeters and more). Double glazing with an area of 4 m² typically weighs around 80 kilograms, while the weight of similarly sized triple glazing can reach up to 160 kilograms. As the size of the surface increases, the use of plastic window profiles of class A – defined by the standard ČSN EN 12608 – is not only a sensible but essentially a necessary decision.

The stability and load-bearing capacity of the profiles are determined not just by standards but are also verified by a series of demanding tests at the manufacturer. "Windows and doors made from our profiles undergo rigorous testing at the certification and testing center in Sendenhorst, Germany. They must withstand impacts from a pendulum weight of fifty kilograms or endure vertical pressure in the corner of the frame ranging from 200 to 800 newtons. Converted to kilograms, this corresponds to a load of about 20 to 80 kilograms, which our products can withstand without damage," explains Milan Klepsa.

text and photo VEKA