Lay Styrodur under laminate as impact sound insulation

On a laminate floor, the insulation of the impact sound is usually the top priority. In living rooms and on storey ceilings, heat-insulating properties are also welcome, but usually of secondary importance. Styrodur is hard and stable and can be laid directly under laminate. A vapor barrier may be required depending on the masonry.

Styrodur and the alternatives

The rigid foam sheets made of Styrodur or XPS (extruded polystyrene) are designed for high pressure loads, depending on the design. If they are used with ground contact and water pressure, they have to withstand significantly higher pressure than under a laminate floor.

  • Also read - Laying Styrodur under the flooring
  • Also read - Laying a laminate with impact sound insulation
  • Also read - Laying Styrodur as insulation under the screed

When choosing impact sound insulation, Styrodur is also on the shortlist because of its cost, ease of processing and good insulating effect. Alternatives are:

  • Hardboard
  • cork
  • Hemp and flax
  • PE foam (polyethylene)

Expanded polystyrene, Styrofoam, is not suitable because it is too elastic and soft. The different insulation materials have the following properties:

  • Wood fiber panels reduce impact noise by around three percent. Their thermal resistance is around 0.10 watts per square meter and Kelvin (W / m²K). They are completely recyclable. Unsuitable for underfloor heating.
  • Hemp and flax are pressed into felt sheets. They absorb up to twenty percent of the impact sound. They offer 0.05 W / m²K heat transmission and are recyclable.
  • Cork also insulates about three percent of the impact sound and has a resistance of 0.04 W / m²K. It can be processed appropriately, laid on underfloor heating and is completely recyclable. The risk is decomposition from moisture and mold. Some treated products are suitable for underfloor heating.
  • Plastic foam made of polyethylene insulates up to thirty percent of the impact sound, depending on the design. The thermal resistance is between 0.01 and 0.06 W / m²K. The material is insensitive to moisture and cannot be recycled.
  • Styrodur or XPS has a resistance of 0.23 W / m²K and insulates up to 15 percent. The non-recyclable panels cannot be used on underfloor heating.

Vapor barrier

When laying Styrodur, a PE film must be used as a vapor barrier on floors that tend to form moisture. It is placed between the floor and the insulation layer. A typical example is the ground floor above an unheated cellar.

Tips & Tricks If you compare the products and costs for Styrodur, you will come across different information on the pressure load. The cheapest product classes already have sufficient strength under laminate.