Concrete Substrate

Schluter-DITRA and Schluter-DITRA-XL

Specifically designed as an underlayment for ceramic and stone tile

Ceramic and stone tiles are durable, easy to maintain, and hygienic, representing the ideal surface coverings. However, today’s lightweight construction methods can make the installation of hard surface coverings particularly challenging. In order to protect the integrity of the tile assembly, an underlayment that performs multiple functions is required.

Schluter-DITRA and Schluter-DITRA-XL are specifically designed to allow the installation of ceramic and stone tile over any even and load-bearing substrate. The integration of four functions—uncoupling, waterproofing, load-distribution, and vapor management—makes consistent results viable through the use of Schluter-DITRA or DITRA-XL.

Every substrate presents unique challenges

There are various challenges associated with the installation of hard surface coverings on concrete substrates. To begin, the coefficient of thermal expansion of concrete is close to twice that of ceramic tile. Additionally, tile contractors are often expected to install tile over young concrete (concrete cured less than 28 days). However, rigid surface coverings installed over young concrete are susceptible to damage as a result of shrinkage during curing.

Pre-stressed/ post-tensioned concrete slabs are also commonplace in today’s construction environment. Although pre-stressing is used to help control deflections in concrete structures, these slabs are still subject to deformations caused by changes in moisture, temperature, and loading. Many concrete slabs on or below grade are subject to moisture migration, which can be problematic. Furthermore, these structures experience the same deformations as stated above.


Schluter-DITRA/ Schluter-DITRA-XL’s uncoupling function protects the ceramic or stone tile covering by neutralizing the differential movement stresses between the concrete substrate and the tile, thus eliminating the major cause of cracking and delaminating of the tiled surface.


Schluter-DITRA/ Schluter-DITRA-XL’s waterproofing ability not only protects the substrate from moisture and harmful substances, it also slows the drying of fresh concrete, which reduces the chances of cracking and curling of the slab.

Vapor Management

The free space beneath the Schluter-DITRA/ Schluter-DITRA-XL matting provides a route for any residual moisture in the concrete slab to escape. This allows the installation of DITRA or DITRA-XL and the tile covering as soon as the slab can be walked upon. Vapor management is also essential for slabs subject to moisture migration.

Support/ Load Distribution

Since Schluter-DITRA and Schluter-DITRA-XL are virtually incompressible within the tile assembly, the advantages of uncoupling are achieved without sacrificing point load distribution capabilities. This allows DITRA or DITRA-XL to be installed  in commercial and industrial applications exposed to heavy vehicular traffic, provided the type, format, and thickness of the tile is appropriate for the application.

By addressing all of the challenges associated with today’s fast construction methods, Schluter-DITRA and Schluter-DITRA-XL provide a durable installation system for ceramic and stone tile over concrete substrates.

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