Schlüter®-DITRA

Application and function

Schlüter-DITRA, in combination with a ceramic or natural stone covering laid in adhesion, constitutes a steam pressure compensation and separation system.

It also allows you to create a waterproofing system for the substrate. The polypropylene sheath has a dovetail-shaped hollow square structure with the innovative “Easyfill” geometry and features an “Easycut” pre-incision grid on the surface.

On the back it is covered with a non-woven fabric.

The support for laying the membrane must be clean, flat and load-bearing. For the application of DITRA, spread a layer of compatible adhesive on the support with a suitable spatula (a notch of 3 x 3 mm or 4 x 4 mm is recommended). The fiber fabric guarantees the mechanical anchoring of the sheath to the underlying adhesive, allowing for good adherence to the substrate. Pay attention to the open time of the adhesive.

The sheath must not remain visible but must be covered with bonded coatings. The anchoring of the adhesive on the upper part of the sheath occurs through the undercut structure of the squares of the sheath. The gluing of the ceramic covering directly on the DITRA must be carried out following the rules of good practice in force.

Features summary:

a) Desolidarisation:
Schlüter-DITRA separates the glue-laid flooring from the substrate, neutralizing the transmission of tension resulting from the different expansions between the substrate and the covering, which are therefore not transmitted to the flooring. On critical substrates it also acts as a bridge over the cracks, thus preventing them from reaching the surface layer.

b) Waterproofing:
Schlüter-DITRA is a waterproof polypropylene sleeve with high vapor barrier capacity. In combination with a ceramic or natural stone glued covering, it is possible to create a waterproofing system that protects the substrate from damage caused by the penetration of humidity. In this case the joints, the connections with walls and fixed elements and the closure of the open sides of the sheath must be made following the instructions in this technical data sheet. Classes of exposure to water: W0-I to W3-I according to DIN 18531-5 E 18534. The system is also supplied with abP certification*.

c) Steam pressure vent:
The intercommunicating channels on the back of Schlüter-DITRA allow the compensation of the vapor pressure deriving from damp substrates.

d) Load distribution:
On the floor, the DITRA sheath must be covered with ceramic tiles of a size, thickness and compressive strength suitable for the intended use and in any case with a size of no less than 5 x 5 cm and a thickness of no less than 5.5 mm. The sheath homogeneously distributes the loads present on the floor through the square cavities filled with glue and separated from each other by hollow ribs, transferring them directly to the support. For this reason, floors laid on DITRA are so resistant. When choosing the format, thickness and compressive strength of the ceramic, to ensure adequate resistance, account must be taken of the stresses to be expected, for example the possible presence of high static and/or dynamic loads (e.g. in commercial or public) and/or important point loads (e.g. grand pianos, shelving, pallet trucks). In this regard, we note the provisions of the ZDB in force in Germany regarding the laying of “Ceramic floors with high mechanical resistance”. In areas subject to high loads, pay particular attention to completely fill the cavities between the sheath and the tile and ensure full bed laying of the ceramic over the sheath. It is good practice to protect ceramic flooring from knocks with hard objects.

e) Tear resistance:
Through the mechanical anchoring that is created under the sheath between adhesive, non-woven fabric and support and, above the sheath, between adhesive and square cavities, Schlüter-DITRA establishes a good adhesion of the ceramic coating with the support. Schlüter-DITRA can be used for both walls and floors. For wall installation, the use of dowels for additional anchoring may be indicated.