Impact sound insulation Underlay

What is footfall sound and walking sound?

In connection with room acoustics, you will repeatedly come across the two terms "impact sound" and "walking sound". Walking noise is the sound that is produced by the movement of people or animals as well as by the running of washing machines etc

It is heard in the room itself, e.g. as the clatter of heels on parquet flooring. If the sound is transmitted into adjacent rooms, it becomes impact sound. With a footfall sound insulation you always achieve a walking sound reduction. However, these two sound reductions are not equal.

The different types of insulation material

The acoustic insulation material can either be made of natural materials such as wood fibre boards or cork, or be made of plastic.

Fibreboard consists of crushed wood residues that are heated and pressed into boards. Wood own adhesives are used for this. These boards are 100% recyclable

Their walking noise reduction is clearly below that of cork or plastic. But they dampen the impact sound quite well

They are comparatively cheap to purchase. Due to their ability to absorb water at high humidity and release it again at low humidity, they also have a positive effect on the room climate. However, this insulation material is not suitable for damp rooms such as the bathroom or kitchen. The boards would swell up by absorbing (too much) moisture.

Cork is a good sound insulator due to its natural structure. It is made from the bark of the cork oak.

The air bubbles trapped in the material dampen the footfall noise. This means that less walking noise is generated and therefore less impact sound. Cork is 100% recyclable

This insulation material is offered both as panels and as roll material. It not only insulates sound, but also heat. Cork should therefore not be laid over underfloor heating systems

This material is also not suitable for use in damp rooms. It would easily mold there due to the moisture.

Acoustic insulation materials made of plastic are polyethylene foam mats (PE foam mats), PE film or polystyrene foam boards. The PE films used here are not identical to the films used as vapour barriers (protection against moisture)

These insulation materials are offered in different thicknesses as rolls or panels. The following applies here: The thicker the material, the stronger the sound insulation

The PE foam mats can have an integrated vapour barrier. Unfortunately these plastic materials are not 100% recyclable. Their price is between 1 €/m² and 10 €/m²

The polystyrene insulation material is not suitable for installation over underfloor heating. PE foam mats, PE films and polystyrene foam mats can also be used in damp rooms.

Heavy foam underlays are a mixture of plastic and mineral materials. This insulation material has the advantage that it insulates sound but not heat. It is therefore ideal for installation over underfloor heating systems.

Which insulation for which floor covering?

In general, the more rigid the floor covering is, the stronger the sound insulation must be. Vinyl and design floors therefore require the least insulation. Its soft material itself acts as a sound insulator

For this reason, a thin PE film is usually sufficient for acoustic insulation with these floor coverings. Click vinyl can also be harder, however. Then a stronger insulation is required. Pay attention to the manufacturer's instructions.

All materials are suitable for laying under laminate and parquet flooring with the exception of PE foil. PE foam is also not recommended. His air bubbles would have flattened out after a few months. Then there is no longer any sound insulation

Important for the selection of the insulation is the sufficient thickness of the material. In addition, when laying over underfloor heating or in damp rooms, you must ensure that the material is suitable for this purpose.

If you are laying the floor covering on a mineral substrate, such as screed or concrete, you should always install a vapour barrier. Practically speaking, there are numerous acoustic materials that already contain them. BUT: When laying on non-mineral floors, such as an old wooden floor, you must not install a vapour barrier

Any residual moisture must be able to escape from the wooden floor. Otherwise you risk the floor decomposing over time.

The correct acoustic insulation is extremely important. They should not save money here under any circumstances. It is difficult and costly to correct errors in acoustic insulation retrospectively.

You can obtain these materials from Parquetkaiser

Parquet Kaiser offers a wide range of acoustic materials:

• Polystyrene roll material with integrated vapour barrier

• EPS insulation underlays with vapour barrier as folding board

• PE foam underlays

• Fibreboard

• Cork insulation material as roll material

• Heavy foam mats

The most important features at a glance

• Walking noise reduction - wood fibre board and cork: 3%

• Reduction of walking noise - Polystyrene: 15

• Reduction of walking noise - PE foam: 16 % to 20

• Sound absorption - low expansion foam mat: 35 % to 45

• Reduction of impact sound: depending on the material 16 dB to 20 dB

• compensates for small unevenness in the floor

• Thermal resistance: depending on material type and thickness: 0 to 0.23 Km²/W

• tested for harmful substances

• Costs: between 1 and 10 €/m²

What should be observed for underfloor heating systems?

In the case of underfloor heating, you must ensure that the combined thermal resistance of any vapour barrier, the acoustic insulation material and the floor covering does not become too great. The greater this resistance is, the better the thermal insulation. However, this is undesirable here, as the heat from the underfloor heating should be able to enter the room through the floor covering

As a rule, the resistance should be less than 0.15 Km²/W. Ideal here for parquet and laminate are low-expansion foam underlays that do not insulate the heat. For vinyl and design floors these underlays are usually too thick. In these cases, plastic materials are recommended, for example a PE film.

The insulation materials made of natural products such as wood or cork are not suitable for installation over underfloor heating due to their good thermal insulation properties.

The installation of the footfall sound insulation

Please check the subfloor before installation. It must be clean, dry, resistant to tension and pressure and level. Make sure that the building moisture (new building) or residual moisture (old building) is not too high

If in doubt, ask a specialist. The acoustic material is laid over any vapour barrier and under the floor covering.

For rolled material: Roll out the insulation material on the floor. Cut the material with a cutter knife. The individual sheets of the material should butt together

Use adhesive tape to prevent the sheets from slipping. Once you have laid the insulation material, you can immediately continue with the floor covering.

For acoustic insulation boards: Lay the boards butt to butt. Fix the plates against each other with adhesive tape to prevent them from slipping. To cut the panels to size, it is best to use a cutter knife. Once the entire area has been covered with the insulation material, start laying the floor covering.

If you want to store the insulation material for a longer period of time, please make sure that it is stored in a cool, dry place and protected from UV radiation.