Schlüter-DITRA-DRAIN-STU  Self-adhesive joint tape

To ensure the full functionality of Schlüter-DITRA-DRAIN mats, the abutting seams between the individual matting elements must be fully covered. We have specifically developed the easy-to-handle, self-adhesive joint tape DITRA-DRAIN-STU for this purpose.

Product image DITRA-DRAIN-STU 1©Schlüter-Systems KG
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General product information

How to install this product

  1. Always check that the substrates on which DITRA-DRAIN is to be installed 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 placing the bonded waterproofing assembly and installing DITRA-DRAIN. The waterproofing layer must have an adequate slope for drainage.
  2. If using DITRA-DRAIN 4, apply a standard dry set mortar to the substrate on the previously described substrate with a notched trowel (6 x 6 mm). The recommended notching for DITRA-DRAIN 8 is 3 x 3 or 4 x 4 mm. The selection of the tile adhesive to be used with DITRA-DRAIN depends on the corresponding substrate. If using covering materials with a side length exceeding 30 cm, we recommend a water-binding tile adhesive for rapid curing and drying of the mortar.
  3. Embed the DITRA-DRAIN sheets, which must have been cut to size beforehand, in the applied adhesive, and immediately press them in place with a float or roller. If using DITRA-DRAIN 4, check that the inverted truncated pyramid chambers are filled with mortar after the installation. The curing time of the adhesive must be observed. For efficient installation, keep DITRA-DRAIN tightly stretched with light tension when placing it on the substrate. The individual membranes are placed with abutting joints, overlapping the lateral fleece edges.

    The self-adhesive DITRA-DRAIN-STU joint tape is available for cut edges that have no fleece edge.

  4. To prevent any damage to the installed DITRA-DRAIN mat or detachment from the substrate, it is recommended to protect the area, e.g. by setting out running boards (particularly in the centre areas used for material transport).

    Special protective measures may be necessary for outdoor installations, e.g. to shield against direct sunlight or precipitation.

  5. Tiles or natural stone coverings can be installed immediately after adhering the DITRA-DRAIN mat, using the thin-bed method. All coverings must be solidly embedded in the adhesive.

    The notch size of the trowel must match the tile format. Observe the curing time of the adhesive. In outdoor areas, the dry-setting thin-bed mortar and the coverings must be waterproof and weather resistant.

  6. The covering can be grouted with a suitable material once it is ready to bear weight.
  7. In outside areas, the open drainage space in the edge area must be covered with a profile such as Schlüter-BARA-RT or an anchoring panel without fully closing the drainage joint.
  8. Follow the instructions given here and in other relevant technical regulations to install movement joints for perimeter, edge and transition profiles.


We recommend our profile types Schlüter-BARA and -DILEX for edging profiles, movement joints and floor-wall transitions.

Areas of application/substrates for Schlüter-DITRA-DRAIN


As an uncoupling and drainage mat, DITRA-DRAIN 8 is especially suitable for stairs in outdoor areas for stress relief between the substrate and the tile covering and for channeling any accumulating water in the drainage area. In addition, DITRA-DRAIN 8 protects the bonded waterproofing assembly KERDI 200 (see product data sheet 8.1) and enables quick curing of thin-bed tile adhesive with subaeration. The bonded waterproofing assembly must have a sufficient slope in the area of the steps.

Make sure that DITRA-DRAIN 8 adhered to the riser does not protrude over the surface of the step to completely channel away any accumulating water. Cover the joints with the joint tape DITRA-DRAIN-STU. At the bottom of the stairs, the drainage water from DITRA-DRAIN 8 must be able to run into a drainage space or be channeled into a drainage system. In the exposed edge area of the stairs, a 5 cm strip of 9 mm Schlüter-KERDI-BOARD (see product data sheet 12.1) can be adhered in the drainage area, and a tile strip can be placed on the covering with Schlüter-KERDI-COLL-L (see product data sheet 8.4) as a water barrier or splashguard.

We recommend the use of adequate stair nosing profiles (such as Schlüter-TREP-E) for edge protection of thinner coverings and to improve anti-slip properties.