Our house is about to start exterior finishing. Our plasterer suggested applying a leveling layer over the top layer (mineral, country house style). Does anyone here have any experience? He said this coating protects against algae growth and makes the stucco really white. And then you won't need a painter's coat.
My painter is not very familiar with the leveling coat (he was honest about that) and said that it probably wouldn't last that long and that a coat of paint would be needed. Does anyone here have any experience? Do I need a leveling coat and is it an alternative to a final coat?
To even out irregularities in the color tone of the plaster, a leveling layer is applied. And, of course, it is also a protection for the plaster. The paint coat is usually at least two coats, which in itself makes the paint more durable (abrasion/washing with mineral paints, for example). Paints are mostly similar (with the same base).
Also, don't apply a leveling coat too quickly, there is no difference in durability.
How should your plasterer's leveling coat be any different than a "regular" painter's coat?
It's just the first layer, the type of finish you can coordinate with both your plasterer and your painter (e.g. silicone resin, etc.). At least that's how it works for us and all other builders.
There are also plaster systems with additives that prevent algae/fungal growth. Therefore, a coating is not necessary for that reason alone.
Just in case others also run into this problem: No, this is not a substitute for painting the facade.