Surface preperation for plastering

When a surface is to be plastered, the surface is prepared in the following manner.

All mortar joints of the wall for plastering are rough and project, so that the plaster can be keyed or held. All joints and surfaces are thoroughly cleaned with a wire brush and ensured to be free from oil, grease etc. If the surface is smooth or the plastering wall is old, the mortar joints are at least taken out. to a depth of 12 mm to bond the plaster.
Projections of more than 12 mm are closed on the surface to achieve a uniform surface of the wall and also to reduce the consumption of plaster.
Likewise, all cavities and holes within the surface are already properly filled.
All woodwork is roughened for plastering.
Finally, the wall mortar joints and surfaces are thoroughly washed, moistened with water and kept for at least 6 hours before plastering.