ᐅ Plaster Application Marks with Q2 Finish Agreement

Our interior plasterer has completed the lime plaster (Weber174). On almost all walls, the marks from the finishing trowel, in the form of grooves and scratches, are clearly visible. We understood that lime plaster does not have a perfectly smooth surface, but we had expected at least no visible tool marks. The contractor was contracted for a Q2 finish, and we always emphasized that we want to paint the plaster directly. The contractor repeatedly assured us that the painter would fill the grooves by using a lambswool roller. However, the painter has now said that this will not work with the planned silicate paint.

The plaster has already dried quite a lot, and we are now looking for advice on how to further treat the walls to eliminate these marks.

Unfortunately, the only solution is to apply putty multiple times and sand it down.

Damn. Does the typical surface texture of lime plaster remain with this method? Or can you see differences between untreated and treated areas? Could lime smoothing be an alternative, or would that have other disadvantages?

Well, you would need to fully skim coat the surface to make everything smooth.
I’m not familiar with lime smooth plaster.
Another option might be to use lime paint right away and apply it with a thick-nap roller and a thick layer of paint. That would almost look like a textured roller finish. This could be an alternative that might require fewer steps.

Thanks, I will discuss this with the painter.

What do you consider a typical surface finish for lime plaster? I assume the surfaces are troweled? They can also be smoothed, scratched, or creatively treated.

The Weber render is a base coat and can be covered with various mineral plasters. It can also be applied in two layers; in that case, the second layer should be applied thinly the next day. Large tool marks should not be visible then.

Q2 is, of course, a rather simple, standard surface, so you shouldn’t expect high quality. For higher standards, you would have had to specify Q3. What kind of mineral paint will be applied? Dispersion silicate or pure silicate? You can also apply something over dispersion silicate, but this shouldn’t be the main purpose of the paint. Lime paint is not much thicker either, or you might soon need to apply a slurry coat—for example, Keim Intact as a primer or mixed in.

I think this is a communication issue between the plasterer and the client. Achieving a nice wall surface with Q2 is optimistic. If a finer surface is desired, two layers should have been applied. Then, for example, a fine lime plaster or a smooth finish. It would have been best if you had included a photo as well.