CERESIT CT 83

Features and Benefits

For fixing Expanded Polystyrene (EPS) boards for thermal insulation of buildings

Properties

  • high adhesion to mineral substrates and EPS-boards
  • very good working parameters
  • resistant to weather conditions
  • possibility for machine application

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Ceresit CT 83 mortar is designed to apply EPS-boards within Ceresit ETICS (External Thermal Insulation Composite Systems) with a light-wet method Ceresit Ceretherm. CT 83 mortar is used for applying to the newly erected objects as well as the buildings to be thermo renovated. The applied boards require additional fixing by means of mechanical anchors, i.e. proper expansion pins made of plastic. Ceresit CT 85 or CT 87 mortar should be used to apply fibre glass armoured layer on the EPS-boards. In case of the walls insulation with façade mineral wool boards, Ceresit CT 190, CT 180 or CT 87 mortar should be used.

Documents and Downloads

Technical Data Sheet
CERESIT CT 83
Download TDS

Step By Step

Preparation of the substrate

 

CT 83 has very good adhesion to sound and carrying substrates, such as wall, plaster and cement substrates free from grease, bitumen, dust and other substances decreasing adhesion. The adhesion to the existing plasters and paint coatings should be checked before starting the application. ”Hollow” plasters should be removed. Substrates with high water absorption, e.g. walls made of aerated concrete blocks or silicate blocks should be primed with Ceresit CT 17 and left for drying for at least 4 hours. Before fixing EPS-boards the adhesion of the mortar should be checked by fix polystyrene boards (10x10 cm) to the prepared substrate and tear them of after 2-3 days.CT 100 compound is ready to use. Before starting work, it should be mixed until homogeneous consistency is achieved. If necessary, 1% of water can be added to achieve the necessary consistency. Mixed mortar should be spread evenly on the surface of the boards with the use of a notched trowel, with 6-8 mm notches. The fibre glass mesh is immediately spread on the prepared layer and embedded with the use of a metal spreader and smoothed down. While doing this, a reserve of about 10 cm of the adjacent strips of mesh should be maintained.

Preparation of the adhesive mortar

 

The ready mortar should be applied with a trowel along the board edges forming a strip of 3-4 cm wide and a few spots with the diameter of approx. 8 cm. The board should be pressed to the wall with a few slight blows of a long float. The properly applied mortar when pressed should cover minimum 40% of its surface. In case of even, smooth substrates the mortar should be applied by means of a toothed long float (teeth 10–12 mm). The boards should be fixed tightly one at the other in one surface with the preservation of ”brick like manner” of vertical connection.

Installation of the insulation boards

 

The board should be pressed to the wall with a few slight blows of a long float. The properly applied mortar when pressed should cover minimum 40% of its surface. When CT 83 is set (after approx. 2 days), any unevenness of the boards should be ground with abrasive paper, then the boards should be additionally reinforced with mechanical anchors.

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