I striped the wallpaper from the hallway/staircase to make way for some rewiring and chasing. These were reskimmed by prof plasterer I then carried out the usual repairs on the remaining parts of the wall to make it good for painting. The walls were a combination of bare plaster (where chasing had been done and subsequently skimmed) and in others a layer of paint on it which I think was a watered emulsion.
I painted the walls with neat superwhite Dulux SuperMatt I have used before with good effect and was impressed by is opacity and thickness on plaster. As I new it would the first coat highlighted minor grooves, dents etc in the walls which I subsequently filled with a fine filler. These were sanded and then a second coat of Supermatt was appled. The filled areas were completely hidden and I was impressed by the finish.
However the following day after everything was dry I have noticed hairline cracks that are too fine to fill, they are in the paint (not the plaster), rather like old porcelain. The paint is firmly stuck and not coming off (it is even tough when sanded).
The cracking is not in any particular place ie. over the skimmed plaster or the old painted area and it is not all over but in patchy areas.
I am unsure to proceed with my finishing coloured emulsion in case the cracking carries through. Should I apply a basecoat to the 'cracked' areas or is there something else I could try.
Sorry for the ramble but I gave you all the details I could.