Features and Benefits

For fixing Expanded Polystyrene (EPS) boards and Mineral Wool boards as well as for applying a thin armoured layer for thermal insulation of buildings


  • 2 in 1 – does not need priming before the application of plaster
  • considerably lower consumption
  • high adhesion to mineral substrates, EPS and mineral wool
  • vapour permeable
  • flexible
  • reinforced with fibres
  • resistant to scratches and cracks
  • resistant to weather conditions

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Ceresit CT 87 mortar is designed to warm up external walls of the buildings by application of external thermal insulation composite system using EPS- or mineral wool façade boards. It is an element of following ETICS from Ceresit: Ceresit Ceretherm Premium or Ceresit Ceretherm Wool Premium and Ceresit Ceretherm Express. CT 87 mortar is used for fixing of EPS- or mineral wool façade boards and for applying the reinforcing protection layer to insulate the newly constructed objects as well as older buildings to be thermo-renovated. CT 87 is additionally reinforced with fibres, therefore it is more resistant to the formation of cracks and hairlines. The application of CT 87 (colour, surface and organic modifiers) allows for omitting the substrate preparation process by priming with the priming paints before the application of any Ceresit plasters. The content of special light fillers gives the more flexible, light and homogenous consistency, it is easier to be stirred, applied and spread, thus increasing the efficiency of the mortar.

Step By Step

Substrate and product preparation


Armoured layer application - when the EPS adhesive is set (after approx. 2 days), any unevenness of the boards should be ground with abrasive paper, then any loose particles of insulation materials should be carefully brushed whereas the boards should be additionally reinforced with mechanical anchors.

Reinforced layer application


CT 87 should be poured into the measured amount of cool clean water and stirred with the drill by means of a mixer until the homogenous mass is obtained without lumps. Armoured layer application: The ready mortar should be spread along the surface of the boards by means of a toothed long float with the size of a teeth 10-12 mm. Only in case of mineral wool boards, is is necessary to apply so called "priming" with CT 87. The glass fibre mesh should be applied on the fresh mortar, ir should be inmersed by means of a metal long float and fillet smoothly. The properly inmersed glass fibre should not be visible, it shold be completly inmersed in the adhesive mortar. It is necessary to use the approximately 10 cm ovwerlaps of the neighbouring mesh belts.