Schlüter DITRA 25 D30M Bonding and Decoupling Membrane 3005m Roll new version

Joint Covering DITRA 25

Joint Covering DITRA 25 is a polyethylene sheet with interlocking square indentations, on the reverse side equipped with a fleece fabric.

Joint Covering DITRA 25 is used in conjunction with tile coverings as a sealing vapor pressure equalization layer for back moisture and as a decoupling layer on problematic substrates. The substrate must be level and load-bearing. To bond DITRA 25, a suitable thin-bed mortar matching the substrate is applied with a notched trowel, recommended 3 x 3 mm or 4 x 4 mm. DITRA 25 is then fully bonded with the fleece side facing the mortar, with the fabric mechanically anchored in the adhesive. The open time of the adhesive must be observed.

The tile covering is installed according to applicable standards using the thin-bed method directly onto DITRA 25, with the mortar anchoring into the interlocking square indentations of the DITRA 25 mat.

Summary of functions

• Decoupling: DITRA 25 decouples the covering from the substrate, neutralizing stresses caused by different deformation behaviors. It also bridges stress cracks from the substrate and prevents them from transferring into the tile covering.
• Sealing: DITRA 25 is a waterproof polyethylene sheet with relatively high vapor diffusion resistance. When properly installed at joints, wall connections, and penetrations, a tested bonded waterproofing with the tile covering can be achieved. DITRA 25 has a general building authority approval (abP) in Germany and is marked with the CE symbol. Moisture exposure class according to abP is 0, B0, as well as A and C.
• Waterproofing in Bonded System: DITRA 25 complies with ETAG 022 for bonded waterproofing and holds a European Technical Assessment (ETA) with CE marking. Moisture exposure class according to ETAG 022 is A and C.

For areas where CE conformity or compliance with the abP general building authority approval is required, only system-verified thin-bed mortars should be used. These mortars and their test certificates can be requested at the address provided in this data sheet.

Protection against moisture

DITRA 25 protects the substructure from damage caused by penetrating moisture and aggressive substances.

Vapor pressure equalization

DITRA 25 allows vapor pressure equalization through the open air channels on the underside in the ribbed areas, accommodating back moisture influence.

Load distribution and transfer

Tile coverings installed on DITRA 25 in floor areas should be at least 5 x 5 cm in size and have a minimum thickness of 55 mm. DITRA 25 transmits traffic loads acting on the tile covering directly into the substrate via the mortar-filled square indentations. This results in high load capacity for the tile covering. In areas with high traffic, such as commercial zones, tiles must have sufficient thickness and stability for the specific application. The guidelines and tile thicknesses according to the German ZDB leaflet "Mechanically highly loadable ceramic floor coverings" must be observed.

In heavily loaded areas, tiles must be fully embedded. It should be noted that the contact area of DITRA 25 covers approximately 50% of the total surface, which may reduce the pressure resistance under high point loads. Impact loads with hard objects should be avoided on ceramic coverings.

Adhesive bond

DITRA 25 ensures a good bond of the tile covering through the anchoring of the fleece fabric with the thin-bed mortar to the substrate and the mechanical anchoring of the mortar in the interlocking indentations, with laboratory test values of approximately 0.02 Nm/m². DITRA 25 can be used for both wall and floor applications. Additional reinforcement dowels can be installed in wall coverings if needed.