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.
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).
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.
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.