Key Facts

CR 61 Renovating upercoat plaster

Renovating undercoat plaster compliant with WTA standards for producing layers up to 10 mm

Properties

  • Vapour-open
  • Negligible shrinkage
  • Hydrophobic
  • Mineral
  • For outdoor and indoor use
  • Amount required: about 9.0 kg/m2 for each cm of plaster thickness

Description

Ceresit CR 61 is used as renovating undercoat plaster on damp and salty walls and concrete surfaces in order to produce dry surface of basement walls and facades. It is especially designed for renovation of historical monuments or damp and salty walls. CR 61 may be used for large surfaces and minor repairs. It can be applied on low load bearing substrates with high salinity.
CR 61 with addition of Ceresit CC 81 contact emulsion may provide an “open work” scratch coat which will improve adhesion of further layers. Together with CR 62 and CR 64, it forms a special system designed for the renovation of old buildings.

Step By Step

Substrate Preparation

Ceresit CR 61 is adhesive to strong load carrying, clean, dry and damp substrates free from any substances decreasing the adhesion. The surface must be rough and porous to ensure good adhesion. The existing layers, the destroyed plaster or rotted parts of the walls should be removed to the height of at least 80 cm over the damp or salted sphere, thus uncovering the carrying substrate. The weathered joints should be removed to the depth of 20 mm, and then filled with the plaster CR 62 or lime mortar. Salty discolouration should be removed with steel brushes. The surface of walls and concrete should be moistened. On the moistened mat substrate there should be open work structure applied with the plaster CR 61 diluted to the proper consistency with the water solution of the emulsion Ceresit CC 81 (1 part of emulsion to be mixed with 3 parts of water). The rendering coat with the thickness of approximately 5 mm must cover evenly 50 % of the substrate surface. The renovation plaster should be applied after the rendering coat becomes hardened, minimum after 24 hours.

Application

The content of the packaging should be poured to the amount of 6.75 l clean, cold water and mixed manually or in a mixer until the homogenous mass without lumps is obtained. If need be, a small amount of water should be added to achieve the proper consistency. Mixing should last not longer than approximately 5 minutes. CR 61may be mixed and fed with a plastering machine. First deep losses should be filled e.g. empty joints. After the mortar becomes set it is possible to apply the basic plaster layer. Plaster should be applied in layers the thickness of which amounts at 10 mm. Plaster should be applied manually or mechanically and smoothen with scantlings. CR 61 is a substrate layer, its fresh surface should be brushed and left for hardening in order to obtain good adhesion for the plaster CR 62. The fresh plaster should be protected against fast drying and for minimum 24 hours it should have damp condition to mature. After the plaster hardens and dries (after 48 hours at least) it can be covered with renovation plaster CR 62. In case of application of CR 61 as a plaster to smoothen the surface it can be coated with silicate paint CT 54 (at least after 3 days) or materials with high vapour permeability (after 2–3 weeks).