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Soundproof door: The effective solution for a quiet environment

Soundproof doors are more than just barriers against noise. They are key elements for a quiet and pleasant environment. Thanks to their special design and choice of materials, they offer an effective solution for reducing unwanted noise and creating a quiet environment.

Focus on sound insulation

In a world that is increasingly permeated by noise, the importance of soundproofing is growing. Whether in residential areas, offices or industrial facilities, protection against annoying noise can make the difference between comfort and discomfort. In this context, soundproof doors play a crucial role. They are not just simple doors, but rather effective solutions against unwanted noise. From choosing the right soundproof door to correct installation, there are many aspects to consider in order to achieve optimum sound insulation.

In this guide, we discuss the basics of soundproofing, how soundproof doors work and how they are constructed, requirements and standards as well as practical tips for installing soundproof doors.

  • The basics of sound insulation
  • Soundproof doors: Guidelines and soundproofing classes according to DIN standard 4109
  • Function and structure of a soundproof door
  • Soundproof doors - the Westag door range
  • Installing soundproof doors - important tips and tricks
  • Conclusion

The basics of sound insulation

The importance of soundproof doors in different environments

Sound insulation is of crucial importance in various environments such as homes, offices and industrial plants. In homes, external noise from traffic, neighbours or other sources can have a significant impact on the quality of life. Here, soundproof doors can make an important contribution to minimising the transmission of this noise and creating a quieter living atmosphere.

In the office, a pleasant working atmosphere is crucial for the productivity and well-being of employees. Soundproof doors between offices or in meeting rooms help to reduce noise levels and promote concentration. This enables employees to work more efficiently.

In industrial plants, where loud machines or production processes are often operated, sound insulation is of great importance in order to protect the health of employees and comply with statutory noise protection regulations. Soundproof doors play an important role here in controlling noise in work areas and improving working conditions.

The use of soundproof doors is therefore an essential part of a comprehensive soundproofing concept, as they help to minimise sound transmission and create a quieter and more pleasant environment for residents, employees or workers.

What is sound?

Sound is a vibration in an elastic medium (such as water, metal, wood, air) that travels away from the sound source; similar to water into which a stone falls, waves of different sizes are formed. Sound waves have different frequencies (pitches) and amplitudes (volumes).

How is sound measured? 

Sound is measured in decibels (dB), a unit for assessing the loudness or intensity of sound. The decibel scale is logarithmic, which means that every increase of 10 decibels represents a doubling of the sound intensity.

dB (A): Noise level at the point/area of origin | d=deci, B=Bell, A rated according to curve (A)

Soundproof doors: guidelines and sound insulation classes according to DIN standard 4109

DIN 4109 is a German standard that deals with sound insulation in building construction. It defines various sound insulation classes that determine the required sound insulation in buildings. The standard specifies requirements for structural sound insulation to ensure that buildings are constructed in such a way that sound immissions are reduced to an acceptable level.

In the following table you will find all sound insulation classes at a glance:

  ClassesDIN 4109Requirements required refernces value (Rw,R)Detection reference value Rw (Rw,P)

Basic soundproofing classes as per DIN 4109

SK271127≥ 27 dB≥ 32 dB
SK322232≥ 32 dB≥ 37 dB
SK373337≥ 37 dB≥ 42 dB
increased soundproofing as per DIN 4109-54SK403,540≥ 40 dB≥ 45 dB
SK42442≥ 42 dB≥ 47 dB

Requirements acc. to DIN 4109

1 Entrance doors to apartments (with internal corridor, standard property insert classroom doors) | 2 Hotel and hostel rooms, and hospital rooms | 3 Entrance doors to apartments (without internal corridor, hostels, hospitals) | 4 To be agreed in the building contract

The DIN 4109 standard also specifies measurement methods and assessment parameters for evaluating the sound insulation of building components such as walls, ceilings and doors. In addition, the standard contains requirements for airborne sound insulation, impact sound insulation and installation noise.

Function and structure of a soundproof door

To ensure that the soundproof door provides sufficient protection against noise, the structure and use of the material is crucial. The structure of a soundproof door consists of several layers that are located inside the door leaf and have a strong insulating effect. Our soundproof doors are equipped with a full chipboard insert or sound-insulating door insert in accordance with DIN 4109 and, in combination with the included floor seal, contribute particularly well to sound reduction.

Sufficient insulation is particularly important for soundproof doors, which cannot be achieved with honeycomb or tubular chipboard inserts, for example. The quality or insulation of the door frame is also important to ensure that noise can be absorbed. The installation of the frame, e.g. using foam, and adequate sealing of the door and frame also contribute to sound insulation. Plastic seals, for example, which are attached to the rebate of the door or frame, are suitable as seals.

Incidentally, the soundproofing function is not visible from the outside, meaning that soundproof doors hardly differ in design from standard interior doors.

Soundproof doors - Westag Türen range

Discover our range of soundproof doors, including SK27/1, SK 32/2, SK 37/3, SK 40/3.5 and SK 42/4. All our doors are certified to DIN 4109 and provide sound insulation to ensure a quiet and comfortable environment. An overview of our sound insulation certificates can be found here

Installing a soundproof door - important tips and tricks

1. Careful selection of the soundproof door: choose a door that has been specially developed for soundproofing and meets the requirements of your environment. Take into account the sound insulation value (Rw value) of the door and make sure that it complies with applicable standards and regulations in your neighbourhood.

2. Correct door dimensions: Make sure that the door opening is measured correctly to ensure a precise installation. The soundproof door should be carefully fitted to ensure that there are no gaps through which sound can penetrate.

3. Qualified installer: Hire a qualified professional to install the soundproof door. An experienced installer can ensure that the door is installed correctly and that all the necessary seals and mounting elements are fitted correctly.

4. Careful sealing: Ensure that all door edges and openings are carefully sealed to minimise sound leakage. Use sealing materials to ensure that the door is hermetically sealed.

5. Floor and wall preparation: Before installing the door, the floor and walls should be carefully prepared to ensure a level and stable base. Unevenness or voids can affect the sound insulation performance of the door.

6. Readjustment and inspection: After installation, the soundproof door should be carefully checked and, if necessary, readjusted to ensure that it is working properly and that there are no sound leaks. Regular maintenance and inspection of the door is also important to maintain its long-term performance.

By following these tips and ensuring that the soundproof door is properly installed, you can maximise sound insulation performance and create a quiet and comfortable environment.


Soundproof doors play a crucial role in soundproofing rooms. Thanks to their special design and insulating materials, they provide an effective barrier against sound transmission and minimise unwanted noise from outside. Careful installation and maintenance of soundproof doors is also crucial to ensure their maximum sound insulation performance.

With the right measures, soundproof doors can help improve comfort, privacy and quality of life in various environments such as homes, offices, hotels and industrial facilities. Overall, soundproof doors are an important component of soundproofing and help to create a quiet and pleasant environment in which residents, employees and visitors can feel comfortable.

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