Kerdi is a pliable, sheet-applied, bonded waterproof membrane and vapor retarder with limited crack-bridging capabilities. Kerdi features a modified polyethylene (PEVA) core with non-woven polyproplyene on both sides to anchor the membrane in the thin-set mortar. Kerdi was developed as a waterproofing membrane to be used in conjunction with ceramic and stone tile coverings. Tiles can be installed directly on Kerdi using the thin-bed method. Other trowel-applied covering materials, such as plaster, can also be used. It is ideal for use in tiled showers, bathtub surrounds, residential steam showers, and other tile applications in wet areas. Kerdi eliminates water damage which can lead to mold and mildew.
| KERDI | H = 100cm. L = 3000cm |
1. The substrate must be clean, even, and load bearing. The thin-set mortar used for bonding Kerdi must be appropriate for the substrate, and it must penetrate and engage the Kerdi fleece. Cut Kerdi to size prior to application.
2. Apply thin-set mortar to the substrate using a 1/4" x 3/16" (6 x 5mm) V-notched trowel, which features a 1/8" x 1/8" (3 x 3mm) square-notched design (Note the open time of the mortar). Press Kerdi fully into the bond coat. Work the Kerdi into the mortar by applying pressure to the membrane with the flat side of the trowel (held at an angle) in smooth, diagonal sweeps. Air bubbles must be avoided.
3. Seams can be constructed by overlapping the edges of the Kerdi 2" (5cm) using Schluter-SET, Schluter-ALL-SET, Schluter-FAST-SET, or unmodified thin-set mortar, or by abutting the edges and covering the joint with KERDI-BAND using Schluter-SET, Schluter-ALL-SET, Schluter-FAST-SET, or unmodified thin-set mortar.
4. For inside and outside corners, adhere pre-formed KERDI-KERECK-F corners. For floor/wall connections, use KERDI-BAND. Install KERDI-SEAL-PS pipe seals at showerhead, body sprays, etc. and KERDI-SEAL-MV at the mixing valve. As an alternative to KERDISEAL- PS/-MV, KERDI-FIX or other suitable sealant can be used to seal pipe protrusions and protect moisturesensitive solid backing panels at the mixing valve.
5. Connections to fixed building elements can be achieved by using KERDI, KERDI-BAND, or KERDI-FLEX in conjunction with KERDI-FIX, suitable trowel-applied waterproofing materials (such as urethane or similar), that require atmospheric moisture to cure, or other suitable sealing compounds.
6. Kerdi shall be separated at existing expansion, structural, and flexible edge joints. Cover the joints with KERDI-FLEX. To allow for greater movement, the center section of the KERDI-FLEX can be tucked into the cavity of the expansion joint prior to bonding.
7. Once the entire membrane—with seams, corners, and connections—has been completely bonded, and therefore waterproofed, the covering may be applied.
Note: Water testing of the assembly. Prior to setting tile, wait 24 hours to allow for final set of the mortar before testing to ensure waterproof performance of the assembly at seams and connections.
8. For tile installations using the thin-bed method, apply Schluter-SET, Schluter-ALL-SET, Schluter-FAST-SET, or unmodified thin-set mortar directly to the exposed Kerdi surface and install the tiles, ensuring full coverage. For acid-resistant coverings, use an epoxy adhesive to set and grout the tile.
For complete installation guidelines and warranty criteria for Kerdi in showers, steam showers, and bathtub surrounds or KERDI-DS in steam rooms, please download the Schluter Systems Shower System Installation Handbook and view the installation videos.
Ditra is a polyethylene membrane with a grid structure of square cavities, each cut back in a dovetail configuration, and an anchoring fleece laminated to the underside. The anchoring fleece is embedded in thin-set mortar to provide a mechanical bond to the substrate. Tile is installed over Ditra using the thin-bed method in such a way that the mortar becomes mechanically anchored in the square, cutback cavities of the matting. Designed specifically for ceramic tile and dimension stone installations, Ditra serves as an uncoupling layer, waterproofing membrane, and vapor management layer that accommodates moisture from beneath the tile covering. Further, Ditra performs all these functions while still providing adequate support/load distribution for the tile covering. The combination of these four essential functions allows for the successful installation of tile over a wide range of substrates, including plywood / OSB, concrete, gypsum, heated floors, etc. Ditra is 1/8" (3mm) thick, which minimizes tile assembly thickness and reduces transitions to lower surface coverings (e.g., carpet, engineered wood, and vinyl). Ditra allows for ceramic tile application over single-layer plywood or OSB subfloors on joists spaced up to 19.2" (488mm).
Uncoupling
Tile has been successfully installed for thousands of years by incorporating an uncoupling layer, or forgiving shear interface, within the tile assembly. Ditra provides uncoupling through its open rib structure, which allows for in-plane movement that effectively neutralizes the differential movement stresses between the substrate and the tile, thus eliminating the major cause of cracking and delaminating of the tiled surface.
Ditra provides reliable waterproofing in interior applications. Its polyethylene composition protects the substrate from moisture penetration, which is particularly important in today’s building environment where most substrates are moisture-sensitive.
Vapor management. The distinguishing feature of Ditra is the existence of free space created by the configured channels on the underside of the matting. The free space provides a route for excess moisture and vapor to escape from the substrate that could otherwise cause damage to the tile layer above. Thus, Ditra effectively manages moisture beneath the tile covering.
Support/load distribution. When placed on a solid foundation, columns or pillars can support tremendous loads. The same physical principle applies to Ditra installations. Column-like mortar structures are formed in the cutback cavities of the matting. Loads are transferred from the tile covering through these column-like mortar structures to the substrate. Since the matting is virtually incompressible within the tile assembly, the advantages of uncoupling are achieved without sacrificing point load distribution capabilities. The ability of Ditra installations to support and distribute heavy loads while preserving the integrity of the tiled surface has been verified through extensive laboratory and field testing, including applications exposed to vehicular traffic.
| DITRA | H = 100cm. L = 3000cm |
1. Using a thin-set mortar that is suitable for the substrate, apply the thin-set mortar (mixed to a fairly fluid consistency, but still able to hold a notch).
For DITRA use a 1/4" x 3/16" (6mm x 5mm) V-notched trowel, 5/16" x 5/16" (8mm x 8mm) V-notched trowel, which features a 11/64" x 11/64" (4.5mm x 4.5mm) square-notched design.
2. Apply Ditra to the floor, fleece side down. Solidly embed the matting into the mortar using a float, screed trowel, or roller, making sure to observe the open time of the bonding mortar. If the mortar skins over prior to matting installation, remove and reapply. Slowly move the roller from one end of the matting to the other, slightly overlapping successive passes.
3. Lift up a corner of the matting to check coverage. Proper installation results in full contact between the fleece webbing and the thin-set mortar. Simply abut end and side sections of adjacent sheets. Note: Coverage may vary with mortar consistency, angle at which the trowel is held, substrate flatness, etc. If full coverage is not achieved, remove and reapply, making sure to verify proper mortar consistency and application.
4. Tile can be installed over Ditra immediately; no need to wait for the mortar to cure. Fill the cut-back cavities with Schluter SET, Schluter ALL-SET, Schluter FAST-SET, or unmodified thin-set mortar and comb additional mortar over the matting using a trowel that is appropriate for the size of the tile. Solidly embed the tiles in the setting material. Periodically remove and check a tile to ensure that full coverage is being attained. Back-buttering is a useful way to help ensure proper coverage, particularly when installing large-format tiles (e.g., 12" x 12" (305mm x 305mm) and larger).
Waterproofing
The following steps are required for waterproofing only:
1. At the joints, fill the cut-back cavities with Schluter SET, Schluter ALL-SET, Schluter FAST-SET, or unmodified thin-set mortar, approximately 8" (203mm) wide, centered over the joint.
2. Comb additional Schluter SET, Schluter ALL-SET, Schluter FAST-SET, or unmodified thin-set mortar over the joint using a 1/4" x 3/16" (6mm x 5mm) V-notched trowel or the Schluter Kerdi trowel, which features a 1/8" x 1/8" (3mm x 3mm) square-notched design.
3. Using the flat side of the trowel, firmly press the 5" (127mm) wide Schluter KERDI-BAND into the mortar to ensure 100% coverage and to remove excess mortar and air pockets.
4. At all wall junctions, apply KERDI-BAND as described in steps 1-3, ensuring a minimum of 2" overlap on to Ditra.
Notes: KERDI-BAND must overlap Ditra at seams and at floor/wall transitions by a minimum of 2" (50mm) in order to maintain waterproof integrity. In some applications the vertical section of the floor/wall transition will not accept a bond to Schluter SET, Schluter ALL-SET, Schluter FAST-SET, or unmodified thin-set mortar. Connections to such elements can be achieved using Schluter KERDI-FIX or suitable trowel-applied waterproofing materials, such as those that require atmospheric moisture to cure (e.g., urethane sealant).
For complete installation guidelines and warranty criteria please refer to the downloadable Schluter -Ditra Installation Handbook and view the step-by-step installation videos.
KERDI-BOARD-SN is a prefabricated shower niche that is fully sealed, quick to install, and integrates with KERDI and KERDI-BOARD shower assemblies. The larger niche sizes include a KERDI-BOARD shelf that can be installed at any height to create separate compartments within the niche.
| KERDI BOARD SN | 305mm x 152mm x 89mm 305mm x 305mm x 89mm 305mm x 508mm x 89mm 305mm x 711mm x 89mm |
Kerdi Board SN over solid backing:
1. Determine desired location and trace around the outside of the KERDI-BOARD-SN flange, making sure the lines are level and plumb. Cut and remove the wallboard such that the niche will be supported on both sides by the studs or other wall framing.
2. Insert the niche and fasten to the studs using wood or metal screws, placing the fasteners approximately 1/4" (6mm) from the edges of the niche. Fasten all corners and limit fastener spacing to 12" (30cm).
3. Connections between the niche and walls are made using KERDI membrane, applied with Schluter-SET, Schluter-ALL-SET, Schluter-FAST-SET, or unmodified thin-set mortar (mixed to a fairly fluid consistency, yet still able to hold a notch). Apply the thin-set mortar using a 1/4" x 3/16" (6mm x 5mm) V-notched trowel or the Schluter KERDI-TROWEL, which features a 1/8" x 1/8" (3mm x 3mm) square-notched design. Apply the membrane over the wall and embed into the mortar throughout its entire surface to ensure proper adhesion. Remove any air pockets. The membrane is subsequently cut to match the niche opening.
Kerdi Board SN over wood or metal framing:
1. Determine desired location and trace around the outside of the KERDI-BOARD-SN flange, making sure the lines are level and plumb. Cut and remove the KERDI-BOARD such that the niche will be supported on both sides by the studs or other wall framing.
2. Insert the niche and fasten to the studs using wood or metal screws and KERDI-BOARD-ZT washers, placing the fasteners along the seam between the KERDI-BOARD and the niche. Fasten all corners and limit fastener spacing to 12" (30cm).
3. Seal the seams between the niche and walls using KERDI-BAND with Schluter-SET, Schluter-ALL-SET, Schluter-FAST-SET, or unmodified thin-set mortar ensuring a 2" (50mm) overlap in all directions.
Note: When using the prefabricated shelf, determine the desired height of the shelf and mark with a level line. Set tile up to that line on the back and sides of the niche. Butter the sides and back of the shelf with Schluter-SET, Schluter-ALL-SET, Schluter-FAST-SET, or unmodified thin-set mortar and solidly embed it in the niche, resting on the previously installed tile. The shelf may be raised at the back to create a slope, or the tile may be set on a slope, to prevent water from pooling in the finished application.
