Schlüter®-KERDI/KERDI-KEBA | Schlüter-Systems


Application and Function

Schlüter-KERDI is a crack bridging waterproof membrane made of soft polyethylene, which has been covered on both sides with a special fleece webbing to anchor the membrane in suitable tile adhesive.

Schlüter-KERDI features imprinted gridlines on one side for easier cutting. In addition to indicating how much material is left, the imprint also shows the minimum overlap width of 5 cm for working with multiple membrane sheets.

Schlüter-KERDI was developed as a bonded waterproofing assembly with ceramic tile and natural stone coverings and is therefore suitable for applications in accordance with the German standards DIN 18531*, DIN 18534, and DIN 18535*. Water exposure classes according to DIN 18534: W0-I to W3-I*.

Furthermore, Schlüter-KERDI features the national technical approval (abP) required in Germany.

Moisture load class according to ZDB: 0 to B0 and A, B and C. Schlüter-KERDI features European Technical Approval (ETA) pursuant to ETAG 022 (watertight covering kits) and bears a CE mark.
* With abP and/or in compliance with ETA according to ETAG 022. Please contact our Technical Department for further information regarding use and installation.

The waterproofing membrane should be bonded to an even, load bearing substrate with an appropriate adhesive. The tiles are laid directly on Schlüter-KERDI using the appropriate adhesive and bedding for the chosen tile or stone. Other suitable trowel applied covering materials or plaster may also be used.

Schlüter-KERDI-DS is a waterproofing membrane and vapour barrier bonded to a tile covering, e.g. for use in swimming pools and spa areas, as well as for commercial applications with high humidity levels.

Vapour barriers are suggested for moisture sensitive substrates such as wood, plasterboard and gypsum plaster.

Accessories for Schlüter-KERDI include internal and external corners, as well as pipe collars.Schlüter-KERDI-PAS sets – consisting of a KERDI-MV collar and a special plastic sleeve – are available for installations involving existing pipe protrusions located within the waterproofing plane that are to be fitted with an internally threaded tap extension. To seal butt joints or corner joints, Schlüter-KERDI-KEBA, in widths of 8.5, 12.5, 15, 18.5 and 25 cm are available.

Schlüter-KERDI-FLEX, in widths of 12.5 cm or 25 cm, is used to seal over expansion joints or flexible edge joints.



  1. The substrate must be free of bond inhibiting components, be load bearing and even. Any unevenness in the substrate must be levelled prior to the application of Schlüter-KERDI.
  2. The type of bonding adhesive used to apply Schlüter-KERDI depends on the type of substrate. The adhesive must bond to the substrate and mechanically anchor the fleece on the underside of the Schlüter-KERDI matting. Verify the compatibility of all materials prior to installation. If using covering materials with a lateral length ≥ 30 cm, we recommend a water-binding tile adhesive for rapid curing and drying.
    System tested adhesive must be used in areas that require special approval of the authorities. Please contact us at the address shown in this data sheet for more details.
  3. Apply the bonding adhesive to the substrate using a 3 x 3 mm or 4 x 4 mm notched trowel.
  4. Individual courses of Schlüter-KERDI are cut to size. Solidly embed the anchoring fleece on the underside in the adhesive so that its entire surface is bonded. Work the material into the adhesive with the smooth side of a notched trowel or a float, exerting pressure on the Schlüter- KERDI matting in diagonal strokes. Avoid the formation of air bubbles and observe the open time of the bonding adhesive.
  5. Overlap the joints of the KERDI membranes by at least 5 cm or abut the joints and fully cover the joint with Schlüter-KERDI-KEBA, using the sealing adhesive Schlüter-KERDI-COLL-L.
  6. Use the pre-fabricated KERDI corners for internal and external corners. Schlüter-KERDI-KEBA must be adhered to corner joints in the same manner. Use Schlüter-KERDI-KM (pipe collar) for pipe penetrations. Functional connections to fixed structural components can be created as well. Depending on the situation of the construction site, Schlüter-KERDI, -KERDI-KEBA or -KERDI-FLEX can be attached to the adjoining structural element with Schlüter-KERDI-FIX to create a waterproof connection (see Product Data Sheet 8.3, Schlüter-KERDI-FIX).
    6a. Adhere KERDI-KM or KERDI-MV (pipe collars) around pipe penetrations. As an alternative, our KERDI-PAS sets comprise a plastic sleeve and a KERDI-MV collar. The collar is adhered around the pipe protrusion together with the plastic sleeve to ensure reliable waterproofing of the subsequently installed internally threaded tap extension after removing the plastic sleeve.
  7. Clamp or tightly adhere a 50 cm x 50 cm piece of Schlüter-KERDI onto the flange of the floor drains constructed in the thin-bed method as a connector collar. Then bring the Schlüter-KERDI mat within 10 cm of the floor drain and adhere it to the connector collar without leaving air pockets. Schlüter-KERDI-DRAIN is a floor drain specifically designed to allow connections to a bonded waterproofing membrane. This allows the simple and fast connection of Schlüter-KERDI to the floor drain, using the Schlüter-KERDI collar.

    Note regarding floor drains:
    Schlüter-KERDI-DRAIN and Schlüter- KERDI-LINE are components that were specifically developed for connection to bonded waterproofing assemblies. Schlüter-KERDI can be quickly and reliably abutted in these cases with the use of Schlüter-KERDI collars.
  8. Cut Schlüter-KERDI above structural and seismic expansion joints, then cover the joint with Schlüter-KERDI-FLEX. Schlüter-KERDI-FLEX can also be used for flexible finishing edges. Alternatively, Schlüter-KERDI-KEBA may be used, provided a loose fold is left above the joint.
  9. The covering can be installed as soon as the entire waterproofing assembly is tightly sealed at all overlaps, corners and joints. No waiting is required. Note: Do not attempt to remove the membrane before tiling as it may loosen the adhesive bond to the substrate.
  10. For the installation of tile, apply dry setting thin-bed adhesive directly over Schlüter-KERDI and fully embed the tiles in the adhesive. Suitable reactive resin adhesives and grout adhesive must be used for coverings that are likely to be exposed to chemicals. xclusively use system-approved thin bed adhesives for areas that require CE conformity or compliance with the general certificate of national technical approval (abP). Please contact us at the address shown in this data sheet for further information about suitable adhesives and the corresponding test certificates.



Schlüter-KERDI-200 is a polyethylene membrane for bonded waterproofing assemblies with a water vapour retardant value of sd = 5.15 m.

Schlüter-KERDI-DS is a special polyethylene membrane for bonded waterproofing assemblies and serves as a vapour barrier with an sd value of more than 100 m, which is considered a vapour barrier in physical construction terms. The waterproofing membrane is 0.5 mm thick and equipped with water vapour blocking additives.

The material is physiologically harmless. Cutting waste of both material types is not classified as hazardous waste. Polyethylene is not UV stable in the long term; the product should not be stored in places with prolonged exposure to direct sunlight.


Since bonded waterproofing assemblies with Schlüter-KERDI do not have the necessary uncoupling function for screed and tile coverings in outdoor areas that are subject to temperature changes, we recommend the use of Schlüter-KERDI in conjunction with Schlüter-DITRA-DRAIN (see product data sheet 6.2) or Schlüter-DITRA (see product data sheet 6.1) for a combined bonded waterproofing and uncoupling function.

Material properties and areas of application

Schlüter-KERDI is waterproof and resistant to most chemicals commonly encountered in tiled environments. It is resistant to ageing, does not rot and is characterised by its elasticity.

Schlüter-KERDI is highly resistant to saline solutions, acid and alkaline solutions, many organic solvents, alcohols and oils. Information regarding its resistance to specific stresses can be provided if concentration, temperature and period of exposure are known.

Verify that the substrate on which Schlüter- KERDI is to be placed is even, load bearing and free from moisture. Surfaces which inhibit proper adhesion must be removed or appropriately treated.

Schlüter-KERDI is suitable for wall and floor surfaces where protection against the penetration of moisture or other harmful substances is necessary.

Surfaces include bath tub surrounds, showers and areas surrounding swimming pools. Industrial applications include, the food industry, breweries and dairies. Swimming pools and similar structures are subject to special requirements. Please contact us for further information if you are planning this type of project.


<a name='kerdi'></a>Schlüter®-KERDI

Schlüter®-KERDI is a polyethylene, waterproofing mat with an anchoring fleece on both sides. It is suitable for waterproofing in conjunction with tiled surfaces on walls and floors. The high water vapour diffusion resistance of Schlüter®-KERDI-DS makes it suitable as a vapour barrier in bonded floor assemblies with tile coverings.

<a name='kerdi'></a>Schlüter®-KERDI

Note: Quantity per pallet has changed


Note: Quantity per pallet has changed

<a name='keba'></a>Schlüter®-KERDI-KEBA

Schlüter®-KERDI-KEBA is a sealing band to seal mat connections and wall to floor connections.

<a name='keba'></a>Schlüter®-KERDI-KEBA


<a name='flex'></a>Schlüter®-KERDI-FLEX

Schlüter®-KERDI-FLEX is a waterproofing band for sealing movement joints.

<a name='flex'></a>Schlüter®-KERDI-FLEX


<a name='f'></a>Schlüter®-KERDI-KERECK-F /-KM

Schlüter®-KERDI-KERECK-F are completely seam sealed, prefabricated parts to produce internal and external corners, while Schlüter®-KERDI-KM are collars for pipes.

<a name='f'></a>Schlüter®-KERDI-KERECK-F /-KM


Schlüter®-KERDI-KERECK/FI 135°




Schlüter®-KERDI-MV are pre-fabricated collars for secure waterproofing (DIN 18534) of pipe penetrations. Due to a fleece-free inner zone, the collars are suitable for use with multiple pipe diameters.


*Centre line 150 mm


Schlüter®-KERDI-PAS sets comprise a pre-fabricated collar and a special plastic sleeve. The collar and this special sleeve are attached at pipe protrusions for secure waterproofing (DIN 18534) of installed plumbing components.


*Centre line 150 mm

<a name='kereck'></a>Schlüter®-KERDI-KERECK

Schlüter®-KERDI-KERECK are pre cut sections to produce internal and external corners. They are also suitable for corner formations that are not perfectly square.

<a name='kereck'></a>Schlüter®-KERDI-KERECK


<a name='kers'></a>Schlüter®-KERDI-KERS

Schlüter®-KERDI-KERS are seam sealed pre fabricated parts for secure waterproofing of corner areas of Schlüter®-KERDI-SHOWER.

Note: Schlüter®-KERDI-KERS 20 products are suitable for showers with side lengths of 80-110 cm. Schlüter®-KERDI-KERS 28 products are suitable for showers with side lengths of 110-150 cm.

<a name='kers'></a>Schlüter®-KERDI-KERS

Schlüter®-KERDI-KERS  Tables 37089


Frequently asked questions


Can I use Schlüter®-KERDI for uncoupling?

Show answer

No, Schlüter®-KERDI serves as a waterproofing layer and does not ensure sufficient uncoupling of the tile covering from the substrate. We recommend the use of our waterproofing and uncoupling membrane Schlüter®-DITRA for this purpose.



Enjoy our videos showing the product itself as well as possible areas of application.

Tiling a shower with linear drainage Part 1 - Waterproofing the walls

Balcony assembly: Loose installation of natural stone on mortar casting mould rings with drainage

Schlüter®-KERDI-BOARD: Tub surrounds

Tiling a shower with point drainage Part 1 - Waterproofing the walls

Gutter system for balconies and terraces: Schlüter®-BARIN

Tiling a shower with linear drainage Center installation

Balcony assembly: Loose installation of natural stone on mortar casting mould rings with drainage

Tiling a shower with linear drainage Wall installation

Tiling a shower with point drainage Part 2

Contact Schlüter-Systems Ltd

Units 3-5 Bardon 22,
Beveridge Lane, Coalville,
Leicestershire, LE67 1TE
Phone: +44 (0) 1530 813396

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We use the following symbols and abbreviations to illustrate our price charts.

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H = height
L = length
B = width

PL = euro pallet 
KV = case packaging 
BV = bundle (there is a 10 item bundle packaging for all the profile types)
P = box packaging 
R = roll
St. = unit