Key Facts

CM 18 "EasyFlex" Flexible thin-bed mortar

Flexible thin-bed adhesive mortar for laying ceramic tile coverings and slabs on critical substrates


  • 30 % higher coverage
  • Very easy to use
  • Extremely long open time
  • Ready for grouting after 12 hours
  • For critical substrates
  • For indoor and outdoor use


CM 18 with Easy flex technology makes your work easier - due to lightweight fillers, CM 18 has 30% higher coverage but less weight.
CM 18 ensures a flexible adhesive bed for placing ceramics, fine stoneware and insulating boards on critical surfaces. For use on heated screeds, balconies, patios and facades, especially on young precast concrete members (at least 3 months old). Can also be used to repair and level unevennesses of up to approx. 8 mm depth prior tile laying.

Step By Step

Substrate preparation

CM 18 adheres to all clean, solid, load-bearing, even, dry  and moist substrates, which are free from substances which can reduce adhesion. Uneven areas or depressions should be levelled before (see Ceresit Flooring and Interior Finishes products). Coatings of insufficient load-bearing strength must be removed. Gypsum/anhydrite or paint coats (not chalking, good adhesion) must be mechanically roughened and freed from dust.
Before applying CM 18 tile adhesive, check the residual moisture of the substrate! Absorbent substrates should be primed with Ceresit primer.
Please refer to the Technical Data sheet!


Pour the content of the packaging into the measured amount of clean, cool water and mixe it with a drill mixer until a homogenous mass without lumps is obtained. It is necessary to wait for 5 minutes (maturing time) and then mix it once again. If necessary, carefully add water until the desired consistency is achieved.


The adhesive should be applied with a suitable notched trowel, depending on the respective tile size. For indoor use, the mortar coverage (contact area) at the back of the tile must be at least 65 %. For outdoor use, a minimum mortar coverage of 90 % is required (combined laying method  should be used i.e. additionally apply a thin layer of the mortar on the tile backside). Fresh excess mortar can be removed with water; hardened material can only mechanically be removed.
Use CM 18 only in dry conditions and at temperatures of +5 °C to +30 °C.