Schluter DITRA 25 Uncoupling Membrane 30m² Roll
Schluter DITRA Matting is a waterproof polyethylene membrane with a relatively high vapor diffusion density. It has a gird structure made up of square cavities, each of which is cut in a dovetail shape and on the underside of which an anchor fleece is laminated. Designed for tile and natural stone installations, Schlüter®-DITRA 25 serves as a waterproofing membrane, a vapour pressure equalisation layer to accommodate construction moisture occurring within the substrate and an uncoupling layer for problematic substrates.
The substrate must be even and load bearing. To bond Schlüter®-DITRA 25, use a bonding adhesive that is appropriate for the substrate. Apply the adhesive using a 3 x 3 mm or 4 x 4 mm notched trowel. The anchoring fleece on the underside of Schlüter®-DITRA 25 must be fully engaged in the adhesive to provide a mechanical bond to the substrate. Please observe the open time of the bonding adhesive.
Using the thin-bed method and following all applicable industry standards, set the tile or stone covering directly on the Schlüter®– DITRA 25 in such a way that the tile adhesive becomes mechanically anchored in the square, cut back cavities of the Schlüter®– DITRA 25 matting.
Summary of functions
Schlüter®-DITRA 25 uncouples the floor covering from the substrate and neutralises the tensions between the substrate and the tile covering that result from the varying deformations of the materials. Likewise, stress cracks in the substrate are bridged and are, therefore, not transferred to the surface covering.
Schlüter®-DITRA 25 is a waterproof polyethylene membrane with a relatively high vapour diffusion density. Provided the mat joints and the connections to walls and built-in elements are properly installed, Schlüter®-DITRA 25 can be used to create a certified bonded waterproofing assembly with the tile covering. Schlüter®-DITRA 25 features the national technical approval (abP) required in Germany and bears the Ü mark. Moisture exposure class according to abP: 0 – B0 as well as A and C.
Schlüter®-DITRA 25 has the required European Technical Assessment (ETA) as specified in ETAG 022 (bonded waterproofing assemblies) and bears CE marking.
Exclusively use system-approved thin-bed adhesives for areas that require CE conformity or compliance with the general certificate of national technical approval (abP). Please contact us at the address shown in this data sheet for further information about suitable thin-bed adhesives and the corresponding test certificates.
Therefore, Schlüter®-DITRA 25 protects the substrate against damage due to moisture penetration and aggressive substances.
c) Equalisation of vapour pressure
The interconnected air channels between the cavities on the underside of the Schlüter®-DITRA 25 matting remain open. This allows moisture in the substrate to evaporate, therefore neutralising vapour pressure.
d) Load distribution (load impact)
Tiles that are installed in floor coverings with Schlüter®-DITRA 25 should have a minimum size of 5 x 5 cm and be at least 5.5 mm thick. The bottom of the square cavities in Schlüter®-DITRA 25, which are filled with thin-bed adhesive, directly transfer the load impact on the tile covering to the substrate. As a consequence, tile coverings installed on top of Schlüter®-DITRA 25 are highly load resistant. If high traffic loads are expected (e.g. in industrial locations), the tiles selected for the installation must be of the corresponding thickness and pressure stability. The requirements of the mandatory guideline “Ceramic Floor Coverings With High Impact Resistance,” published by the German Construction Industry Association (ZDB) must be followed.
In areas with high impact loads, the tiles must be fully embedded in the thin-bed adhesive. The contact surface of Schlüter®– DITRA 25 amounts to approximately 50% of the total surface. This can reduce the load bearing capacity in case of point loads. For high point loads, select a tile thickness that is capable of distributing the loads. Ceramic tile coverings should not be exposed to the direct impact of hard objects.
e) Adhesive properties
Due to the bonding of the anchoring fleece into the thin-bed adhesive on the underside and the mechanical anchoring of the adhesive in the cut back cavities, Schlüter®-DITRA 25 achieves a good adhesion of the tile covering to the substrate (laboratory test values: ~ 0.2N/mm²). Consequently, Schlüter®-DITRA 25 can be used for wall and floor coverings. Anchor plugs may be used with wall coverings if necessary.
- The substrate must be free of bond inhibiting components, be load bearing and even. Any unevenness in the substrate must be levelled prior to the application of Schlüter®-DITRA 25.
- The type of bonding adhesive used to apply Schlüter®-DITRA 25 depends on the type of substrate. The adhesive must bond to the substrate and mechanically anchor the fleece on the underside of the Schlüter®-DITRA 25 matting. Verify the compatibility of all materials prior to installation.
- Apply the bonding adhesive to the substrate using a 3 x 3 mm or 4 x 4 mm notched trowel.
- Individual courses of Schlüter®-DITRA 25 are cut to size. Solidly embed the anchoring fleece on the underside of Schlüter®-DITRA 25 in the adhesive so that its entire surface is bonded and immediately work it into the adhesive using a float or screed trowel. Please observe the open time of the bonding adhesive. When initially positioning Schlüter®-DITRA 25, it is advisable to align and position the matting while slightly stretching it. Application is made easier with a second person. The side edges and ends of individual courses are cut straight and abutted.
Note: If Schlüter®-DITRA 25 is only installed as an uncoupling membrane, side edges and ends of individual courses do not need to be sealed with Schlüter®-KERDI-KEBA. Please refer to the instructions for waterproofing if the membrane is to serve as a waterproofing layer.
- Once installed, the matting must be protected against heavy mechanical loads to avoid loosening it from the substrate or other damage. It is advisable to place running boards (especially in the centre of material transports) to protect Schlüter®-DITRA 25. Other protective measures, such as shielding of direct sunlight or protection from precipitation in exterior applications, may also be required. Carefully remove any moisture that may have gathered in the indentations of the studs before applying the thin-bed tile adhesive.
- Immediately after the Schlüter®-DITRA 25 matting is installed, the tiles can be set using the thin-bed method and using a bonding tile adhesive that matches the requirements of the covering. It is recommeded to fill the square cavities with the smooth side of the trowel and to establish a regular pattern in the bonding adhesive with the notched side of the trowel in one application. The tiles are fully embedded in the adhesive. Fully embedded installation of tiles in accordance with the applicable professional standards is particularly important for coverings with high traffic loads and in outdoor areas. The notches of the trowel must match the format and thickness of the tiles, so as to achieve solid bedding. Please observe the open time of the adhesive. The adhesive bed over Schlüter®-DITRA 25 should not exceed 10 mm.
- For movement joints as control joints, expansion joints, or connection joints please follow the instructions given in this product data sheet as well as the applicable industry regulations.