Schlüter-DITRA-SOUND  Heavy duty PE (polyethylene) mat with integrated fleece

An absolute must, not just in family homes – effective sound insulation. Schlüter-DITRA-SOUND earns full points for this function. The product also stands out for its low assembly height and load transfer to the substrate. Another advantage: the heavy duty PE mat is easy to cut precisely to size with a utility knife. Simply install the mat over thin-bed adhesive and cover the abutting joints with the self-adhesive joint covering tape Schlüter-DITRA-SOUND-KB. The tiles can then conveniently be installed right away. DITRA-S355LV is available in bundles, without packaging, for large scale projects.

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Product image DITRA-SOUND 1©Schlüter-Systems KG
Cross-section drawing DITRA-SOUND 1©Schlüter-Systems KG
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Product image DITRA-SOUND 1
Cross-section drawing DITRA-SOUND 1

General product information

What this product does

Schlüter-DITRA-SOUND is a bonded sound insulation assembly for tile coverings comprising a heavy duty polyethylene mat with an anchoring fleece laminated on both sides. The system was tested by an independent testing institute according to DIN EN ISO 140-8.

An impact sound improvement value (ΔLW) of 13 dB was measured in fully installed Schlüter-DITRA-SOUND assemblies.

The actual improvement offered by the respective assembly depends on the local conditions (structural design) and can deviate from this value. The measured test values therefore may not apply equally to every building situation.

The substrate must be level and load-bearing. Schlüter-DITRA-SOUND is installed in cementitious tile adhesive that is suitable for the substrate, using a notched trowel (recommended size: 3 x 3 mm or 4 x 4 mm). The anchoring fleece on the underside (imprinted side) of Schlüter-DITRA-SOUND is fully embedded and the fabric bonds with the adhesive. The adhesive curing time must be observed.

The tile covering is installed directly over Schlüter-DITRA-SOUND in accordance with the applicable regulations, using the thin-bed method. The thin-bed tile adhesive bonds with the fleece layer on the top side of the mat. This creates a fully bonded system.

Impact sound / structural noise

The transmission of noise to adjacent rooms or lower floor levels, caused e.g. by walking or falling objects, is called impact sound. This causes vibrations in the floor/ceiling structure, which are then passed on as airborne sound.

The human ear perceives a 10 dB impact sound reduction as a 50% reduction of airborne sound.

In addition, the impact sound of e.g. hard shoes, echoes back into the room. This leads to unpleasant reverberations in light structures with hard surfaces, the so-called drum effect. The solid mass of the heavy duty mat prevents this effect.

Summary of functions

a) Sound insulation / structural noise insulation

In addition, the heavy duty mat material absorbs structural noises, e.g. those caused by footsteps, and helps reduce the drum effect.

The low assembly height of approx. 3.5 mm and the excellent sound insulation values of Schlüter-DITRA-SOUND make it an ideal choice for renovation and refurbishment projects in buildings as well as new construction projects.

b) Crack-bridging

Cracks that are only expected to widen slightly without height displacement may be covered with Schlüter-DITRA-SOUND to prevent cracks in the substrate from continuing into the tile covering. If necessary, add an insert to prevent vertical height displacement.

c) Load distribution (load induction)

Schlüter-DITRA-SOUND is a compression-resistant heavy duty mat that makes tile coverings installed on Schlüter-DITRA-SOUND especially durable. The tiles for the corresponding application area must be sufficiently thick and have adequate compressive stability to withstand high traffic loads (max. 5 kN/m², e.g. in commercial areas).

Carefully ensure that tiles in high-stress areas are solidly embedded in the tile adhesive.

The impact of hard objects must be avoided on ceramic coverings.

Tile dimensions should be at least 5 x 5 cm with a thickness of at least 5.5 mm.

How to install this product

  1. The substrate must be load bearing, level and free of components that may inhibit bonding. Any necessary levelling work must be completed before installing Schlüter-DITRA-SOUND.
  2. Cover the edges of the covering at rising walls or structural elements with the self-adhesive edging strip Schlüter-DITRA-SOUND-RSK to prevent stress build-up or sound transmission.
  3. The selection of the cementitious tile adhesive for installing Schlüter-DITRA-SOUND depends on the substrate. The adhesive must bond with the substrate and mechanically attach to the Schlüter-DITRA-SOUND anchoring fleece when curing. A dry setting cementitious tile adhesive is suitable for most substrates. Review any potential material incompatibilities beforehand.
  4. Apply the cementitious tile adhesive on the substrate with a notched trowel (recommended size: 3 x 3 mm or 4 x 4 mm).
  5. Embed the Schlüter-DITRA-SOUND panels, which must have been cut to size beforehand, in the installed adhesive, the printed side of the anchoring fleece facing down. Immediately press them in place with a float or roller, working in a single direction. The curing time of the adhesive must be observed. For efficient installation, precisely align Schlüter-DITRA-SOUND when placing it on the substrate. Install the individual panels with closely abutting joints. Remove any excess adhesive.
  6. Attach the self-adhesive Schlüter-DITRA-SOUND-KB sealing tape over all abutting seams to prevent sound transmission.
  7. To prevent any damage to the installed Schlüter-DITRA-SOUND or detachment from the substrate, it is recommended to protect the area from mechanical stresses, e.g. by setting out running boards (particularly in centre areas used for material transport).
  8. Immediately after adhering the Schlüter-DITRA-SOUND mat, tiles can be installed using the thin-bed method, with a cementitious tile adhesive that meets the requirements of the respective covering. Groove the cementitious tile adhesive with a notched trowel matching the corresponding tile format. All tiles must be solidly embedded in the adhesive. Full contact according to the applicable professional regulations is especially relevant for coverings exposed to high mechanical stresses. Observe the curing time of the adhesive. The adhesive must be able to cure hydraulically or through another chemical reaction in an airtight space without any water evaporation.
  9. Follow the instructions in the data sheet and other relevant technical regulations to install movement joints for perimeter, edge and transition profiles.

Substrates for Schlüter-DITRA-SOUND

Always check the substrates on which Schlüter-DITRA-SOUND is to be installed to make sure they are level, load-bearing, clean and compatible with the materials to be used. Remove all surface components that may weaken the bond. Any levelling, height adjustment or slope compensation must be carried out before installing Schlüter-DITRA-SOUND.


Concrete undergoes long-term structural deformation due to shrinkage. With the use of Schlüter-DITRA-SOUND, tiles may be installed after three months.

Cement screeds

With the use of Schlüter-DITRA-SOUND, tiles may be installed over cement screeds after 28 days. There is no need to measure the residual moisture.

Calcium sulfate screeds

According to the applicable rules, calcium sulfate (anhydrite) screeds may not have a residual moisture level of more than 0.5 CM % at the time of tile installation. In contrast, tiles may be installed as soon as the residual moisture level drops below 1 CM % with Schlüter-DITRA-SOUND. Because calcium sulfate screeds are susceptible to moisture, screeds must be protected against humidity, e.g. moisture seepage on the underside.

Heated screeds

Schlüter-DITRA-SOUND can also be used on heated screeds. In this case, the applicable regulations for conventional heated screeds in conjunction with tile coverings must be observed.

Plywood panels

These materials undergo significant deformation based on the influence of moisture (or fluctuations in humidity). It is therefore recommended to use plywood materials with special water-repellent treatment to protect against moisture. The panels must be thick enough to be sufficiently stable in conjunction with a suitable support structure. The panels must be sufficiently secured with screws. All joints should either be tongue and groove connections or covered with adhesive. Perimeter movement joints of about 10 mm have to be maintained at the transition to upright building structures. Schlüter-DITRA-SOUND neutralises any minor tensions that may occur within the substrate.

Hardwood floors

In principle, ceramic coverings can be directly installed on sufficiently weight bearing, screw-fastened hardwood floors with tongue and groove connections in conjunction with Schlüter-DITRA-SOUND. The wooden substrate should have balanced moisture levels before Schlüter-DITRA-SOUND can be installed. It has proven beneficial to install an additional layer of plywood. Uneven floor surfaces should be levelled with suitable measures beforehand.

Synthetic/vinyl coverings and coatings

All surfaces must be load bearing and pre-treated or suitable for bonding with an appropriate adhesive, in which the Schlüter-DITRA-SOUND anchoring fleece can be embedded. The compatibility of the adhesive with the substrate and with Schlüter-DITRA-SOUND must be verified in advance.


Schlüter-DITRA-SOUND also enables sound insulation assemblies in staircases. It can be used on the various substrate types described above.

What this product is made from

Schlüter-DITRA-SOUND is a compression-resistant heavy duty mat with a thickness of approx. 3.5 mm. A fleece fabric is laminated on both sides. Polyethylene is not UV-stable in the long term; the product should not be stored in places with prolonged exposure to direct sunlight.

Material properties and areas of application

Schlüter-DITRA-SOUND is non-rotting, stretchable and crack-bridging. In addition, it is largely resistant to the effects of aqueous solutions, salts, acids and alkalis, many organic solvents, alcohols and oils.

Product resistance to special local conditions must be verified separately based on the anticipated concentration, temperature and length of exposure. The product has a relatively high water vapour diffusion seal. The material is non-toxic and physiologically harmless.

Schlüter-DITRA-SOUND can be used in a wide variety of application areas.

Product suitability must be verified in applications exposed to chemical or mechanical stresses.

How to look after this product

The cementitious tile adhesive and the covering material installed in conjunction with Schlüter-DITRA-SOUND must be suitable for the respective application area and meet the corresponding requirements.

The use of quick-curing cementitious tile adhesives may be an advantage for certain projects.

It is recommended to protect the centre areas, e.g. those used for material transport, by setting out running boards or other protective coverings over areas where Schlüter-DITRA-SOUND is installed.

Notes on movement joints

Separate Schlüter-DITRA-SOUND over existing movement joints.

Continue the movement joints in the tile covering as specified by the applicable standards. Otherwise, divide large coverings installed over Schlüter-DITRA-SOUND into sections, using movement joints according to the applicable regulations. We recommend using the profiles of the Schlüter-DILEX family. Arrange profiles such as Schlüter-DILEX-BT or Schlüter-DILEX-KSBT over existing expansion joints depending on the anticipated structural movements.

Notes on perimeter movement joints

It is important to prevent stress build-up at the edges of the covering, for instance at upright structural components or at floor-wall transitions. Perimeter movement joints and connection joints must be constructed according to the applicable technical regulations and have sufficient dimensions to prevent stress build-up. Install Schlüter-DITRA-SOUND-RSK 630 as an edging strip in these areas. We recommend the various profile types of the Schlüter-DILEX family for perimeter or connection joints at transitions from floor tiles to wall or skirting tiles.