We have hundreds of spots though. Saw a wall done 2 years ago the top was rubbed up and was speckled with lignite. Top of wall today looks dreadful all blowen looks like bad acne pits!! Uf it was only a few i would def just seal and paint.
No I don't blame the plasterer at all. You would think it is a black stone until u crush it. Wouldn't see it until it is in a rubbed up wall which starts drying out. Sand supplier has admitted fault but we now have hassle of getting windows protected to start chipping it all off!! It's so...
Grin and bear it. We are having same problem I could cry!! How did your rectification of walls turn out. Would really appreciate if could chat to u. Thanks