Schlüter-KERDI-BOARD  Tileable, waterproof backerboard

Schlüter-KERDI-BOARD is a multi-purpose tile substrate for wall areas, that can also function as a bonded waterproofing assembly in conjunction with tile or natural stone coverings. This versatile panel can be used in many applications.

The panel consists of an extruded rigid foam, laminated on both sides with a special reinforcement material and a fleece fabric to facilitate anchoring in the tile adhesive.

Available in thicknesses of 5, 9, 12.5, 19, 28, 38 and 50 mm, KERDI-BOARD covers a broad range of application areas in which a level, waterproof substrate is required for tile or natural stone coverings.

Schlüter-KERDI-BOARD is waterproof and resistant to any chemical stresses that typically occur in conjunction with tiled coverings. Where necessary, KERDI-BOARD can be used to provide certified bonded waterproofing.

So long as the seams and connection areas are properly installed, the backerboard can be used to provide certified bonded waterproofing.

KERDI-BOARD can be used to create tiling substrates on existing carcass masonry, on existing floor substrates of any kind, on stud structures in wood or metal, and for creating standalone straight or rounded partition walls, for cladding over prewall installations or pipes (pipe boxes), for panelling for straight or rounded tubs and showers, for creating kitchen countertops, vanity units, shelving or any other bathroom structures. It is equally suited to creating level substrates for floors when renovating sanitary installations with foot traffic and similar areas.

KERDI-BOARD is easy to cut to size with a utility knife. The product features printed gridlines on the top side for quick and neat installation.

KERDI-BOARD can be glued over its entire surface in wall areas or affixed on spots of thin-bed mortar or other suitable adhesive/mortar. If required, the board can be further anchored using dowels. The product is attached to wood or metal stud structures using the fastening screws included in the product range.

Tiles are laid directly onto KERDI-BOARD, using the thin bed method.

Other suitable rendering materials or plaster layers of a trowelling consistency can also be applied.

Fully embedded Schlüter-KERDI-BOARD

1. The adhesive must bond with the substrate and mechanically attach to the KERDI-BOARD anchoring fleece. A dry setting tile adhesive according to EN 12004 can be used for most substrates. Otherwise, choose another suitable adhesive and review any potential material incompatibilities beforehand.
2. Apply tile adhesive with a notched trowel, either on the substrate or on KERDI-BOARD.
3. Fully embed Schlüter-KERDI-BOARD in the adhesive, creating a bond with the anchoring fleece. The curing time of the adhesive must be observed.
4. The individual panels must have abutting joints and be aligned accordingly.
5. Immediately after adhering KERDI-BOARD, tiles can be installed in the thin-bed method, using a dry-setting tile adhesive that meets the requirements of the respective covering. The notch size of the trowel must match the tile format. Observe the curing time of the adhesive.

Schlüter-KERDI-BOARD adhered with dabs of adhesive

1. Place dabs of adhesive on the KERDI-BOARD panel at intervals of approx. 30 cm and ensure that all board edges are fully supported with adhesive. Depending on the thickness of the layer, these spots may consist of cementitious tile adhesive or a suitable bonding adhesive.
2. Set the panels at the wall, press them in place and align them with a spirit level.
3. Immediately after adhering KERDI-BOARD, tiles can be installed in the thin-bed method, using a dry-setting tile adhesive that meets the requirements of the respective covering. The notch size of the trowel must match the tile format. Observe the curing time of the adhesive.

Note: If the installation does not result in a permanent bond between the adhesive and the substrate, additional mechanical fastening with the corresponding anchors and screws is required.

Schlüter-KERDI-BOARD on stud structures

1. Attach Schlüter-KERDI-BOARD either vertically or horizontally on the properly assembled stud structure and fasten it with screws. If using the support plates, the screws can be set into the abutting joint of the panels. Select the length of the screw such that they penetrate wooden stud structures by at least 20 mm and metal stud structures by at least 10 mm. The spacing between screws should not exceed 25 cm. Depending on the on-site requirements, the panel thickness for stud structures (centre line 62.5 cm) should be at least 19 mm.
2. For vertical placement, install the individual panels with closely abutting joints over the centre of the studs. For horizontal installation, embed all vertical abutting joints that are not supported by a stud with tile adhesive, Schlüter-KERDI-FIX or the double-sided adhesive tape Schlüter-KERDI-BOARD-ZDK. Such abutting joints should be arranged in an offset pattern.

Schlüter-KERDI-BOARD in partition walls

1. The edge of Schlüter-KERDI-BOARD is adhered at a fixed wall so that the KERDI-BOARD partition wall is integrated into the tile covering installed on the wall. If possible, the partition wall should be incorporated between the KERDI-BOARD panels attached to the fixed wall. As an alternative, a matching angle or U-shaped profile of the system may first be fastened to the fixed wall with screws to integrate the partition wall.
2. Partition walls with an exposed side can be stabilised with a U-shaped profile included in the system. If fittings are to be attached to the U-shaped profile, the matching flat plastic profile Schlüter-KERDI-BOARD-ZFP should be adhered to the underside of the U-shaped profile to achieve better support for the screws. U-shaped profiles can also be used in floor and ceiling connections.
3. All vertical and horizontal KERDI-BOARD joints must be sealed with cementitious tile adhesive or KERDI-FIX if applicable. A matching angle or U-shaped profile may be adhered in one or several bed joints to help stabilise longer partition walls.
4. Depending on the individual construction site requirements, such partition walls represent lightweight wall panels without structural analysis. As a general rule, the panels should have a thickness of 50 mm. Panels used for shelf structures may have a thickness of 19 mm or more. This should be determined based on local requirements at the site.

Schlüter-KERDI-BOARD in floor areas

1. Schlüter-KERDI-BOARD is suited for creating level substrates in floor areas when renovating bathrooms with foot traffic and similar spaces.
2. To accommodate KERDI-BOARD in thicknesses of 5, 9, 12.5 and 19 mm, the substrate must be free of components that may inhibit bonding, sufficiently load bearing and level. Complete any necessary levelling work before installing KERDI-BOARD.
3. The adhesive must bond with the substrate and mechanically attach to the KERDI-BOARD anchoring fleece. A dry setting tile adhesive according to EN 12004 can be used for most substrates. Otherwise, choose another suitable adhesive and review any potential material incompatibilities beforehand.
4. Apply cementitious tile adhesive on the substrate with a notched trowel and fully embed Schlüter-KERDI-BOARD in the adhesive, creating a bond with the anchoring fleece. The individual panels must have abutting joints and be aligned accordingly. The curing time of the adhesive must be observed.
5. If the substrate is sufficiently load bearing, KERDI-BOARD from a thickness of 28 mm can also be installed and aligned over spots of thin-bed adhesive or other suitable adhesive. The spots of mortar must be adequately spaced to ensure proper load bearing. Apply tile adhesive over the joints at the panel edges and make sure that joints are located over the spots of adhesive.
6. Prevent the build-up of tension at KERDI-BOARD or the tile covering in the edge areas, for example by installing an edge strip.
7. Immediately after fully embedding KERDI-BOARD, the tiles (minimum size 5 x 5 cm) can be installed in the thin-bed method, using a tile adhesive that meets the requirements of the respective covering. If using spots of adhesive, make sure to allow for sufficient curing until they are properly load-bearing. The notch size of the trowel must match the tile format. Observe the curing time of the adhesive.
8. Follow the instructions of the relevant technical regulations to install movement joints for perimeter, edge and connection joints.

Waterproofing with Schlüter-KERDI-BOARD

Schlüter-KERDI-BOARD can be installed in accordance with the waterproofing standard DIN 18534 applicable in Germany. Water exposure classes: W0-I to W3-I*. In addition, Schlüter-KERDI-BOARD features the national technical approval (abP) required in Germany.

Moisture load class according to ZDB: 0 to B0, as well as A and C.

KERDI-BOARD features European Technical Approval (ETA) pursuant to ETAG 022 (watertight covering kits) and bears a CE mark. System-certified tile adhesives must be used in areas that require CE-compliance or assemblies according to abP (certificate of technical approval).

* With abP and/or based on ETA according to ETAG 022. Our Technical Department will be pleased to provide information on use and installation on request.

We recommend the use of our waterproofing membrane Schlüter-KERDI (see product data sheet 8.1 Schlüter-KERDI) for load class B "containers", (e.g. for swimming pools).

Cover the abutting joints in the surface and in the corner areas of KERDI-BOARD by fully embedding the sealing band Schlüter-KERDI-KEBA in a minimum width of 12.5 cm in the sealing adhesive Schlüter-KERDI-COLL-L. The sealing band must have an overlap of at least 5 cm.

KERDI-KEBA can also be used to create functional connections to fixed structural components such as door and window frames made of metal, wood or plastic. To this end, apply KERDI-FIX on the bonding surface of structural components and KERDI-COLL-L on the bonding surface of KERDI-BOARD and fully cover the entire joint area with sealing band.

The suitability of KERDI-FIX for the respective material of the structural elements must be verified in advance. The feasibility of connections must be assessed based on the conditions of the construction site. Seal all connections with great care.

Separate KERDI-BOARD at existing movement joints or expansion joints and seal the abutting joints with Schlüter-KERDI-FLEX. KERDI-FLEX should also be used for flexible finishing edges.

Rendered and plaster surfaces on Schlüter-KERDI-BOARD

KERDI-BOARD is a suitable substrate for rendered and plaster surfaces as well. These can be surfaces adjoining tiled areas (e.g. half-height walls) or entire walls in other areas.

The abutting joints in the surface and at external and internal corners must be reinforced, along with exposed edges, to be covered with trowel-applied material. Our self-adhesive joint reinforcement KERDI-BOARD-ZSA may be used for this purpose.

Schlüter-KERDI-BOARD is made of an extruded XPS rigid foam with a cement-free reinforcement layer and an anchoring fleece laminated to both sides. The surface of the board is printed on one side with 10 x 10 mm square gridlines.

Material properties and areas of application

Schlüter-KERDI-BOARD is waterproof and resistant to the chemical stresses that typically occur in conjunction with tile or natural stone coverings. Where required, KERDI-BOARD can be used to create a certified bonded waterproofing assembly.

KERDI-BOARD is flat and is resistant to warping even when subject to temperature or humidity stress on one side. The material is age-resistant and highly stable.

KERDI-BOARD is ideal for a wide variety of applications. Product suitability must be verified in applications exposed to chemical or mechanical stresses. The information below can only serve as a general guideline.

Substrates on which KERDI-BOARD is to be installed must be checked for sufficient stability and other project-related requirements. If affixing the product directly, remove anything on the surface that could weaken the bond. Alternatively, the product can be fastened mechanically with appropriate anchors or screws.

For free-standing partition walls, shelves etc. made from KERDI-BOARD, select panels of sufficient thickness. Use reinforcement profiles if necessary.

Used in floors, KERDI-BOARD is only suitable for areas with foot traffic only. Depending on the system, stepping on the board in hard shoes or tapping them with a hard object may produce a hollow sound.

Select the panel thickness and installation method to suit to the flatness of the substrate. Thin KERDI-BOARD (5 mm) must be fully embedded in the adhesive.