Schluter Ditra Uncoupling Membrane

Schluter Ditra Installation Handbook

Schluter Ditra Uncoupling Membrane is one of the most popular underlayments available on the market today. Underlayments are installed under stone and tile coverings to provide a variety of different functions including crack suppression, waterproofing, load distribution, and vapor management.

By using the Schluter Ditra Uncoupling Membrane, the life of a stone or tile installation can be prolonged. With large format tile and thin porcelain tile installations, using an uncoupling membrane is especially important because these types of tile are at a greater risk of incurring cracks.

Schluter Ditra underlayment is an uncoupling membrane that provides crack suppression by protecting the tile or stone covering from the substrate. Movement or cracks in the substrate can translate to the tile causing damaged and cracked tiles. By allowing the tile to move independently from the substrate, the tile is protected.

While thick mortar beds can accomplish this, they can be problematic because of the extra height that is added to the installation. Schluter Ditra Uncoupling Membrane provides this layer of protection without the extra height addition. At only 1/8" thick, Schluter Ditra aides in the transition from tile to many common types of flooring including carpet, wood, and vinyl.

Composed of a polyethylene grid structure with square cavities cut back in a dovetail configuration, the Schluter Ditra Uncoupling Membrane has an anchoring fleece on the underside to provide a mechanical bond to the substrate. The open rib structure of Schluter Ditra provides uncoupling and can be used to protect all types of natural stone, ceramic, and porcelain tile installations by neutralizing movement stresses between the substrate and tile.

Waterproofing and Vapor Management

In addition to the excellent crack suppression capabilities of Schluter Ditra Uncoupling Membrane, it also provides additional functions including waterproofing and vapor management, making it versatile for different stone and tile installation requirements. Suitable for both interior and exterior applications, the polyethylene grid is completely waterproof and will prevent water from penetrating down to the substrate.

Many of today's substrates such as plywood, OSB, and gypsum concrete are water sensitive. By including a moisture barrier for installations around shower and tub surrounds, the tile layer can be protected from possible damage caused by water leaks or flooding. Installations in areas around toilets, dishwashers, and washing machines lines are also prone to water damage and will also benefit from a moisture barrier. When using the Schluter Ditra Uncoupling Membrane for waterproofing, Schluter Kerdi-Band must be used at all joints and seams to make the installation truly waterproofed.

The Schluter Ditra Uncoupling Membrane is also an efficient vapor barrier. Channels on the underside of the matting create free space that allows excess vapor and moisture to escape from the substrate. By allowing the vapor and moisture to escape, the tile layer is kept safe from incurring possible damage. Waterproofing capabilities combined with vapor management make Schluter Ditra an extremely effective moisture control solution.

Load Distribution

The cutback cavities in Schluter Ditra Uncoupling Membrane provide a mechanism for load distribution. Like pillars or columns that are can support incredible loads, the cutback cavities create column-like mortar structures capable of transferring the load from tile covering to the substrate. By transferring the load, the tile covering's integrity can preserved without sacrificing point load distribution. Furthermore, because Schluter Ditra is basically incompressible, the uncoupling functions of the membrane are still achieved.

Substrates

Versatile and easy to install, the Schluter Ditra Uncoupling Membrane can be installed over a variety of substrates including plywood, OSB, concrete, poured gypsum underlayments, and radiant heated floors. All of these different substrates present unique challenges for stone and tile installations. By addressing the problematic properties of a substrate, Schluter Ditra makes stone and tile installations possible over substrates that can traditionally be difficult.

Wood

For wood substrates, changes in moisture content can cause expansion, contraction, bending, and deflection. By providing waterproofing and vapor management, moisture is kept away from the wood from above and as allows an escape route for vapor coming from the substrate itself. The uncoupling function of Schluter Ditra Uncoupling Membrane further provides protection against differential movements between the wood substrate and tile covering, eliminating a common cause of cracking and delaminating of the tile.

Concrete

Concrete has several challenges as substrate when used with ceramic tile and stone installations. In today's fast construction setting, installation over young or not fully concrete is often encountered. As concrete cures, moisture is released. The vapor management capabilities of the Schluter Ditra Membrane allows moisture to escape as the slab cures and tile to be installed as soon as the slab can be walked on. Vapor management is essential for installations over concrete.

Additionally, with a coefficient of thermal expansion is almost twice that of ceramic tile, concrete will have a greatly different rate of contraction and expansion from changes in temperature than tile. Also, as concrete cures, it shrinks. This difference in movement between the concrete substrate and tile puts the tile at greater risk of cracking. The Schluter Ditra Uncoupling Membrane allows the substrate and tile covering to move independently and eliminate a potential cause of cracked tile.

Gypsum

Gypsum concrete present a few challenging problems as a substrate. Gypsum-based underlayments are extremely sensitive to moisture and water and typically require a full cure before any tile or stone can be installed. Like concrete, gypsum concrete also experiences a greatly different rate of expansion and contraction from temperature fluctuations than ceramic tile. With the popularity of gypsum concrete in radiant floor heating installations, it is vital for the installation address the different rates of contraction and expansion.

Schluter Ditra Uncoupling Membrane addresses and neutralizes the differential movement between the substrate and tile covering to prevent cracking. Additionally, the waterproofing and vapor management properties of Schluter Ditra will prevent the reintroduction of moisture while allowing any residual moisture to escape through the underside channels of the membrane.

Schluter Ditra Installation Handbook